HTGSupplys Ask The Doc

How to Adjust pH

2012-01-24T16:23:00.004-06:00

The pH is adjusted by using an acid to lower it or a basei to raise it. There are many products sold by HTGsupply.com, that you can use to adjust your pH. I have used General Hydroponics' pH down and pH up. Many acids and bases are extremely corrosive and dangerous, so extreme care should be used if you are not using a product labeled for hydroponic use.
Always follow the directions of any product you use, but you should start out adding one milliliter per gallon. Wait 15 - 30 minutes, and test your water again. Frequently you will only need 1 to 2 ml of pH Up/Down per gallon of water. Keep in mind you may need additional pH Up/Down if you have hard water. The General Hydroponics Flora Series is pH buffered to facilitate keeping the pH in a favorable range.
Something I will say may surprise you, pH is not as critical as most growers believe. The main point is to avoid extremes in pH. Plants can grow on soils with a wide range of pH. However, the pH does not jump to extremes in a soil. So, the real secret is to make sure you keep your plants in a moderate pH at all times. For most plant species there is an optimum pH in the region of pH 5 to pH 6.5

The most popular componets of pH adjusters are phosphoric acid (to lower pH) and potassium hydroxide (to raise pH). Both of these chemicals are relatively safe, although they can cause chemical burns and should never come in contact with your eyes or mucus membranes. I would recommend using pH adjusters that are diluted to a level that is reasonably safe and easy to use. Concentrated adjusters can cause large pH changes and can make adjusting the pH very frustrating.

It is worth saying again, always add your nutrients to the water a few minutes before checking and adjusting the pH of your solution. The fertilizer will usually lower the pH of the water due to its chemical makeup. After adding your nutrient and mixing the solution, check the pH using whatever method you chose. If the pH needs to be adjusted, add the appropriate adjuster. Use small amounts of pH adjuster until you get familiar with the process. Recheck the pH and repeat the above steps until the pH level is where you want it to be. Once you have done this a few times, you'll know how much to give your plants the first try.

Most of the time, the pH of the nutrient solution will have a tendency to go up as the plants use the nutrients. As a result the pH needs to be checked periodically and adjusted if necessary. To start out, I suggest that you check pH minimally on a daily basis. Each system will change pH at a different rate depending on a variety of factors. The type of growing medium used, the light cycle, the kind of plants and even the age of the plants all effect the pH variations.

Good Growing
Dr. E.R. Myers

Causes of pH Change and How Nitrogen Affects pH

2012-01-17T16:20:00.003-06:00

This is the 200th post on this blog, please search for any topics and if you don't find it E-mail me your question. Thanks for all the questions and comments!
Most varieties of vegetables grow at their best in a nutrient solution having a pH between 5.5 and 7.5 and a temperature between 20 and 22C. (68F-72F). Good growers need to find the best pH for their plants but should always start in this range.

Why does the pH change? A simple explanation as to why the pH changes is that plants will take up nutrients from the water and when these nutrients are taken from the reservoir this changes the pH.

The light cycle also affects pH, you should check the pH at the same time of the light cycle when you check it. If you think you have pH problems, you should check it several times a day throughout the light cycle. If you have an accurate pH meter and keep notes you can actually plot and see how the pH changes for your plants throughout the day.

When you provide light to plants they can do photosynthesis which is a metabolic pathway that produces various ions. During the dark cycle, photosynthesis stops but plants still do cellular respiration and if you are using beneficials they will be respiring too. All this respiration and don’t forget the decomposition of organic matter in the solution leads to pH changes. If you are having pH prolems cleaning out the reservoir can sometimes help, if you have leaves or plant pieces in the reservoir their decomposition can change the pH and can lead to other problems with fungus.

In low light plants take up more potassium and phosphorous from the nutrient solution so the acidity increases (pH drops). In strong intense light plants take up more nitrogen from the nutrient solution how this affects pH depends on the type of nitrogen you are giving your plants.

Nitrogen is the inorganic nutrient required in the largest quantity by plants. Most plants are able to absorb either nitrate (NO3-) or ammonium (NH4+) or both. NH4+ as the only source of nitrogen or in excess is harmful to the growth of many plant species. Some plants yield better when supplied with a mixture of NH4+ (ammonium) and NO3- (nitrate) compared to NO3- alone. Good Growers will experiment to see what ratio is best for their plants. Good growers also know a combination of NH4+ and NO3- can be used to buffer against changes in pH.

Plants grown in nutrient solution containing only NO3- as the sole nitrogen source tend to increase solution pH - hence the need to add acid. But when approximately 10%-20% of the total nitrogen is supplied as NH4+, the nutrient solution pH is stabilized at pH 5.5. You may end up with less NH4+ than you add if you use beneficials. It has been shown recently that micro-organisms growing on plant root surfaces can convert the NH4+ to NO3-.
Good Growing,
Dr. E.R. Myers

E-mail - pH crashes in hydropoinc system

2012-01-12T16:27:00.004-06:00

Hey Doc,
I bought my hydroponics system from HTG but the pH in my system crashes to 4.0 every week or so, how can I stop this or stabalize it?

Thanks for your question. The easiest way is to add pH up. Sometimes pH crashes because of the presence of a large amount of microbial activity in the nutrient solution. If you flush the system each week and generally keep up maintenance of the system you should avoid this scenario. If you are not adding beneficial microbes, you might want to think about adding them. If you check out the HTGSupply.com website and beneficials that are specifically for hydroponics this might help as well.

I will be writing about specific pH adjustment in the next blog, thanks for the question!

Good Growing,
Dr. E.R. Myers

Checking the pH with Hydropnics

2012-01-07T16:26:00.006-06:00

When you are growing hydroponically checking and adjusting pH is a simple but very important thing to do. There are several ways to check the pH of the nutrient solution in your hydroponic system.

HTGSupply.com sells all of these products, look on their webpage under Monitering and Test Equipment. To start, you can use paper test strips which are the most inexpensive way to check the pH of the nutrient solution. These paper strips have pH sensitive dye which changes color when dipped into the hydropinics nutrient solution. You then have to match the color of the strip to a chart to see what the pH is. These test strips are inexpensive, but they can be hard to read, because the colors differences are subtle. If you are going to be trying different nutrients etc. or are seriously into growing hydroponically, you might want to get a digital pH meter.

A step up from the paper test strips are liquid pH test kits. These are more a popular method to check pH for the hobby gardener. These liquid test kits work by adding a few drops of a pH sensitive dye to a small amount of the nutrient solution and then comparing the color of the resulting liquid with a color chart. While slightly more expensive than the paper test strips, they are easier to read and are more accurate and reliable.

The Most high-tech way to check pH is to use the digital meters. These meters come in a huge array of sizes and prices. Unless you are also going to use your pH meter for chemistry, YOU DO NOT REALLY NEED A METER THAT GOES FROM 1-14, you only need a meter that checks pH between 4-9 since that is the range plants need. With most digital pH meters you simply dip the electrode into the nutrient solution for a few moments and the pH value is displayed on an LCD screen.
The problem with hydroponics is that while it gives the grower more control of nutrients and pH it is also easier to mess up. The same goes for a digital pH meter. Digital pH meters are very accurate (when properly calibrated) and fast but they need to be cared for properly however, or they will quit working. The glass bulb electrode must be kept clean and some are required to be wet at all times. What these pH meters are doing is checking the voltage in the water, so corrosion or misuse of equipment will break the device. The pH meters usually need to be calibrated frequently, (Just follow manufactuers instructions) as the meters can drift (give the wrong pH value) and to insure accuracy you must check calibration often. With some digital meters, the tip needs to be stored in an electrode storage solution or in a buffer solution and should never be allowed to dry out
The pH meters are slightly temperature sensitive. Many of the more expensive pH meters on the market have Automatic Temperature Compensation (ATC), which corrects the reading with respect to temperature. On meters without ATC the pH should be checked at the same time of day each time in order to minimize any temperature related fluctuations. Again, you don’t need ATC if you will always check at the same temperature, don’t buy all the bells and whistles if you don’t need them.
Due to the fact that pH meters have a reputation of breaking down without warning it is a good idea to keep an emergency backup for checking pH (paper test strips or a liquid pH test kit), just in case.
Good Growing,
Dr. E.R. Myers

Hydroponics and pH Basics

2012-01-02T04:22:00.030-06:00

Happy New Year! and Happy Birthday P.J.!

The pH is very important in hydroponic gardening. I will talk about some specifics of measuing pH in a later post. The pH is measured on a scale of 1-14 with 7.0 being neutral. Acids are lower than 7 and bases (alkalinity) are above 7.
In order to understand how nutrients affect pH you should know the term pH is a measure of the hydrogen-hydroxyl ion content of a solution. These are the two components if you break apart water H2O (H+ and OH-). Pure water has an equal balance of hydrogen (H+) and hydroxyl (OH-) ions and is therefore pH neutral (pH 7.0). {Substances (molecules or atoms) with a charge are either positive or negative and are termed ions}. Since distilled water is pure water it has a pH of 7.0. This is too high a pH for mos plants so I don't recomend using it without adding nutrients. When you add nutrients to water it can have a pH either higher or lower than 7. If the solution has more hydrogen (positive) ions than hydroxyl (negative) ions then it is an acid (less than 7.0 on the pH scale). Conversely if the solution has more hydroxyl ions than hydrogen it is alkaline (or a base), with a pH greater than 7.0
When the pH is not at the proper level the plant will lose its ability to absorb some of the essential elements required for good growth. This depends on the plant and the nutrient. Some plants need a high amount of iron, and since iron becomes increasingly unavailable to plants as the pH approaches 8.0, these iron needing plants do poorly in basic mediums. For all plants there is a particular pH level that will produce optimum results, good growers experiment until they find their best or optimal pH for their plant(s). This pH level will vary from plant to plant, but in general most plants prefer a slightly acid growing environment (between 5.5-6.5), although most plants can still survive in an environment with a pH of between 5.0 and 7.5.
When pH rises above 6.5 some of the nutrients and micro-nutrients begin to precipitate out of solution and can stick to the walls of the reservoir and growing chambers. If you notice residue or salts in your reservoir when you change the water, you might want to adjust your pH down a bit. To use iron as an example again… Iron will be about half precipitated at the pH level of 7.3 and at about 8.0 there is virtually no iron left in solution at all. In order for your plants to use the nutrients they must be dissolved in the solution. Once the nutrients have precipitated out of solution your plants can no longer absorb them and will suffer deficiency and death if the pH is left uncorrected.
Not all nutrients will affect the pH the same! In other words you can manipulate the pH with the nutrients you add. Good growers will know nitrogen (an element required in large quantities for healthy plant growth) may be supplied in two forms (ammonium - NH4+ or nitrate - NO3-). These two forms of nitrogen when added to the nutrient solution will result in different changes can result in large pH changes.
More on pH to come...
Good Growing,
Dr. E.R. Myers

The pH of Some Commonly Grown Plants Using Hydroponics

2011-12-31T16:23:00.005-06:00

In the previous post I was asked about the best pH, well as usuall my answer is it depends on what you are growing. Below are some nutrients that 'drop out' at various pH's and a few common plants I have grown indoors and their recomended pH growing hydroponically, the pH may need to be different if growing in soil or other mediums.

pH values above 7.5 cause iron, manganese, copper, zinc and boron ions to be less available to plants.
pH values below 6 cause the solubility calcium and magnesium to drop.
pH values between 3 and 5 and temperatures above 26C encourage the development of fungal diseases.

Good Growing and

Happy New Year!

Plant     Optimal pH Range
Beans        6.0-6.5
Broccoli   6.0-6.5
Cabbage   6.5-7.5
Carrots     5.8-6.4
Chives      6.0-6.5
Garlic      6.0-6.5
Lettuce     6.0-6.5
Onions     6.5-7.0
Peas         6.0-6.8
Pineapple 5.0-5.5
Radish     5.6.-7.0
Strawberries 5.6.-7.0
Tomatoes  5.5-6.5

E-mail - Best pH for 8 Site Clone Bucket

2011-12-27T12:31:00.002-06:00

Hello Dr. Myers,
I just bought the 8 site cloning bucket . Can you please tell me what I should adjust the pH of my water to ? Also it came with a cloning gel and hormex... Which one should I use ? Thank you in advance for answering my questions.

Thanks for the question. I have really enjoyed my 8 site clone bucket!!! The pH of the nutrient/water solution, depending on the plants you are growing should be between 5.5 and 6.8. In most cases optimal pH is about 5.8 to 6.3 but this may vary slightly depending on the plant you are growing and the conditions you provide.
Some good growers get optimal results with pH as low as 5.0. I always encourage growers to experiment to see what works best for your grow environment and the particular plants but always keep the pH between 5.0 and 7.0.
You should measure the pH right after you add the nutrient solution to the reservoir (mix well first) because the nutrients will change the pH level of the water. Check the pH level a couple times a day the first time you use the clone bucket but once you know about where the pH will end up with your nutrients you only need to check it about once a week. I actually have not checked pH in awhile with my bucket, I simply change ALL the water each Friday and I use the same fertilizer and have great growth so I know that the pH is good. If this is your first hydroponic growing experience, you will need to check it often to see if you need to adjust your pH. Different nutrients will have different affects on pH and water from different areas will have a different pH so you may need to adjust your pH each week or maybe you will be lucky like me and not have to.
I like hormex, I have written about it on the blog, but since you have 8 clone sites try both on four different plants a few times and see which one works better for you. I’d enjoy hearing back your results!
I will be writing about pH on the blog in Jan. Thanks to your good question.
Good Growing,
Dr. E.R. Myers

Growing Ghost Peppers

2011-12-17T04:27:00.001-06:00

I am going to be doing a test on beneficial bacteria using ghost peppers. These are one of the hottest peppers in the world (they were the hottest in 2007, but have been surpassed by other peppers since then). They are hotter than jalapeño and hotter than habaneras. I used latex gloves when handling the seeds since the hottest part of peppers is the part where the seeds are. It is possible that the ‘hotness’ evolved as a defense mechanism so that animals did not eat the seeds but only the flesh. Or, like many crops the ‘hotness’ could be do to breeding.

The “hotness” is from a substance called capsaicin. There are capsaicin glands near the seeds, usually at the top of the pepper. The placenta is the part where the seed attaches to the pepper pod. In most peppers the number of capsaicin glands are higher toward the end with the stem (The stem is called a peduncle) so if you are ever in a challenge, go first, take a bite by the tip (the tip is called the apex) and let the next guy take a bite closer to the peduncle.

GHOST PEPPERS ARE NOT SOLD IN STORES BECAUSE THEY CAN CAUSE PHYSICAL HARM DO NOT JOKE OR PLAY AROUND WITH THESE PEPPERS! A friend of mine took a little nibble of the apex and his nose and mouth turned red and burned for hours.

The name ghost pepper is actually due to English speakers mispronouncing and/or misspelling its name. Another name for this pepper is Bhut jolokia ( they are from India) The name is based on the region it is from, but if you spell it wrong it is translated as ghost.

Good Growing
Dr. E.R. Myers

E-mail - MH vs HPS Flowering and Vegetative Growth

2011-12-10T16:20:00.003-06:00

Dr. Myers
I recently purchased a 1000w digital system from HTG (http://htgsupply.com/Product-Digital-Greenhouse-1000-watt-HPS-Grow-Light.asp)
I thought I grew with HPS and flowered with MH.(they state that on another web page) I called HTGSupply.com and they say it is just the opposite.
Which is correct?
Also, there are several versions of MH that work with my system an MH 6500K (sounds like a grow bulb to me) an MH Neutral, MH Warm,MH Cool.
What MH bulb should I use and when should I be using them...Thank You very much.

Thanks for your question, it is important to know! Let me try to clear this up...
You grow with MH during vegetative because it has more blue light which promotes vegetative growth. You use an HPS for flowering 1) because it has more yellow light which encourages flowers/fruit and 2) the excess yellow will also cause plants to grow tall and without wind or shaking some plants get lanky and fall over. Plants naturally have slow then no vegetative growth when then flower so this is not such a problem when using the HPS during flowering
If I may quote the HTGSupply.com website, good growers worldwide agree that growing with Metal Halide during the vegetative stage, then switching to High Pressure Sodium for flowering is the way to grow the BEST PLANTS POSSIBLE. This method gives you the thickest, most lush plant and the best yields!

I talked about Kelvin before on the blog (LINK to Kelvin post)
You are right the 6500 K would be for vegetative growth, and it would be the one I would recomend you use for vegetative (It could be used for flowering too). However, for the light you bought, the idea / benefit is the you can use the MH for vegetative and then switch the bulb over to the HPS when you flower, HPS is usually around 2200 K.
Good Growing
Dr. E.R. Myers

E-mail -What you Need to Start Indoor Growing

2011-12-01T16:27:00.000-06:00

Hi Doc,
I have decided to start growing indoors. I have read some of your posts, but can you tell me what is the most important thing when growing indoors. I know you need a light, and a medium but what should I start with, there is just so many choices and I want to start off with the best stuff.
Thanks

Hello, Thanks for your question. I will touch on this topic, but as you said there are a lot of choices, I encourage people to do experiments for themselves, to determine what is best for their plants in their grow environment. I also encourage people to do searches for topics on this blog, I have been writing for three years now. If you don’t find something, send me another E-mail and I will look into it. A lot of my posts are from questions like you ask.

I think you are in the right area, HTGSupply.com is certainly one of the best grow supply stores, and they have a great reputation for great products and great customer support. You should contacts Sales@htgsupply.com with questions about any equipment, and I answer questions about plant biology.

The most important thing when growing anything is genetics. (Please see my posts on Plant Breeding). If you don’t have good genetics, the environment you create really does not matter. Once you get good seeds or cuttings then the next most important thing is a good light. Light drives photosynthesis, which provides the energy for the plant to grow and flower, not the best light = not the best plants.

I also encourage first time growers to grow in soil. It is a very forgiving medium; it has some nutrients, and holds some water but allows for good drainage if it is mixed with things like sand, vermiculite, or perilite. If you are going to grow big plants, use 5 gallon buckets, but 2-3 gallon buckets will be ok for plants under 3 feet tall.

Once you have a good light from HTGSupply.com, you need to keep the temperature between 60 and 80F in your grow area. A spare closet would be a good grow area, but a grow tent will also allow you to grow indoors if you don’t have a spare closet.

That is my recommendations for now, once you get started please feel free to E-mail me any and all questions about plant biology.
Good Growing,
Dr. E. R. Myers

Using a Screen #2 - Increase Yields

2011-11-27T16:20:00.001-06:00

I first was introduced to the idea of growing with a screen from an E-mail from a good grower that was looking to increase their yields.
I have previously talked about using a screen to grow in small spaces. A friend of mine is doing this now so I'd like to add some comments.
First, I mentioned in the using a screen article that you should trim lower branches and leaves to avoid them becoming infected with mold. This is still a good idea, but my friend has not had any problems with mold and she does not trim the branches. She does remove all yellowing fan leaves. She says light getting to the plants is more important than the nutrients that are left in the yellow leaf. I still say it is not a bad idea and you could use these lower branches for cloning. The advantage to using these lower branches for cloning is you can pick the plants that are doing the best or have the best characteristecs (growth habit, color, taste etc.)
Second, I recomended using chicken wire or small holed fencing in my first article. My friend really likes the fencing where there are square 3x4 inch holes. She said the chicken wire holes were too small, it was hard to get the stems through the wire when they had big fan leaves, and it was easier to train the brances with the larger holed fence. She does not even use tie wire etc. She simply keeps the plants growing along the screen until the plants really start to flower, then the plants stop their vertical growth.

I welcome any other commets about growing with a screen,
Good Growing,
Dr. E. R. Myers

E-mail - Hydroponics Set Up - List of Needed Materials

2011-11-20T04:23:00.002-06:00

Hey Doc,
This is my first time working with hydroponics, are there any specific chemicals that are required to start off with? A list perhaps? Thank you for your time...

Hello,

Thanks for your E-mail. I too am just getting into hydroponics, I have been and will be a dirt grower but like with LED's I am expanding my growing ability thanks to good growers like yourself asking questions.

I have had great success with the bubble boy products from HTGSupply.com. The picture below is the proof.

I will start a list, and continue to talk about hydropoinics in the coming posts...

You don't really need any special chemicals, but you will need to monitoer the pH and add the right nutrients to you plant/ the water.
You need a good hydropoinics system, the water needs to be airated or circulated well to oxygenate the water. I almost never recomend first time growers start off with hydropoincs, soil is much easier and forgiving to grow in.

You need a medium for the roots to grow through.

You will need a pH meter too, the problem with hydropoincs is that if you don't monitor the pH the water can get to an extreme pH and nutrients won't be available to the plants no matter what and how much fertilizer you use. I change the water completely every week no matter what the pH to avoid nutrient lock up etc.

You need fertilizer(s) too. Unlike with soil growing you must provide ALL the nutrients to the plant ALL the time. This can mean maximum growth if you know what you are doing, but can mean dead or sickly plants if you don't. Most hydropoinic fertilizers come with instructions on how much to use, follow the instructions.

That is all I have been using and you can see with the 90 watt LED UFO I have gotten great flowering.

More to come on hydropioncs,
Good Growing
Dr. E. R. Myers

Seed Germination in a Plastic Bag

2011-11-12T16:23:00.004-06:00

While I would not recommend this method for small seeds (they should be put directly in the grow medium) a cheap and easy way to germinate seeds is with a plastic sandwhich bag and a paper towel. This allows the grower to see which seeds germinate and then put a germinated seed in a pot. This is a good way to conserve space if growing in a small space. If you can only have a specific number of pots you can start a few more seeds than the number of pots you havea in a bag and put the first seeds to germinate in the pots. I used to keep track of the percentage of seeds that germinated when I had a lot of seeds and stored them (Seed Storage LINK) for long periods of time. After seeds are stored for more than a year less and less will germinate. After 5 years I have very few seeds germinate.

If you are going to use this method, you want to make sure NOT to over water the paper towel. If you can ring water out of it, it is too wet. You can always add a few drops in a day or two if it gets too dry. Do not let the paper towel become total dry either. You should open up bag at least every day to check moisture and to look for seeds that have germinated, (Do you see the germinated seed in the bag below?) I used to use a small object to keep the bag open so the top of the bag did not actually touch the seeds.

Another potential problem is that the roots may grow into the paper towel. If this happens do NOT pull the seed out. The most important part of roots are small little projections called root hairs. These hairs are where water and nutrients are taken in. If you pull the plant out of the towel you could damage the fragile root haris and at such a young age this could kill the plant. The pape towel is what should be torn and then just plant it right along with the plant. It will break down and obviously plant roots can grow right through it.

Good Growing,
Dr. E.R. Myers

E-mail - Soil Gnats, Sand and Nutrients

2011-11-03T14:20:00.022-05:00

Hi Doc,
My question concerns a method i used hastly to get rid of fungus gnats. have already been using azamax with minimal results for awhile. yesterday i got foxfarms dont bug me and sprayed the crap out of the top of soil and the sides and bottoms of the pot. i also put about an inch layer of play sand on the top so they wont want to come back. This seems to be working pretty good actually but what should i do about feeding. I use house and gardens soil an b line. Will the sand filter out my nutrients??

Thanks for your question. You can check out a previous post on soil grant remedies.
No, the sand should not affect nutrients if it is play sand. Some sands have calcium or other minerals that might alter your fertilizer uptake. I used Perilite for the same purpose. You have the right idea, you want to keep the gnats away from their food source and breeding area, damp soil. Try to let the top of the soil/sand in your container dry out 100% before watering again. The more dry the soil the less successful the gnats will be.

One other thing to consider is watering from the bottom. If you are able to, water your plants from the bottom for a week or so in order for the top of the containers to remain dry. Be mindful that your little friends the soil gnats might also figure out they can get to soil from the bottom too. I grew in 5 gallon buckets with lids for trays and it was not possible for the gnats to get to the 3-5 holes I had drilled in the bottom of the buckets for water drainage. I put several inches of perilite on top of the soil after I watered the plants with water I soaked a few cigars (philly blunts) in for a couple days. Nicotine is a natural organic insecticide. You could try that too if you like. I watered the plants with normal fertilizer, then used the nicotine water to just get the top of the soil saturated, I did not want the nicotine to go all the way through the soil, just to stay on top where the gnats are.
Good Growing,
Dr. E.R. Myers

Nutrient Basics - Cobalt

2011-10-22T11:10:00.001-05:00

Cobalt is needed by all animals in trace amounts.Cobalt is a component of vitamin B12 which is essential to most animals and possibly plants
Studies indicate cobalt is essential to many beneficial bacteria that are involved in nitrogen fixation both in legumes and non-legumes. From what I read, the cobalt is actually being used by the beneficial bacteria and the use in plants is still unknown. I would recommend having cobalt in a fertilizer if you are going to use beneficial bacteria of any type. There is still a lot of unknowns about cobalt.
Cobalt is needed in VERY small amounts. It is toxic to people in large amounts, a few grams will kill a 200 pound person so do NOT search out large quantities. You should not touch cobalt with your bare hands. It was used to settle beer foam in Canada a few years ago and it lead to heart problems.

Good Growing,
Dr. E.R. Myers

Nutrient Basics - Molybdenum

2011-10-16T16:22:00.001-05:00

Molybdenum

As I wrap up my nutrient basics series of articles I want to suggest to the good growers that molybdenum and the next post on cobalt are two nutrients that may benefit the beneficial organsims as much or more than the plant it self. Molybdenum is proven to benefit symbiotic nitrogen fixation and it is used by plants for protein synthesis.

Molybdenum deficiencies show up as leaves of young plants are chloritic, leaf margins yellow and curl. Older leaves become abnormally large, while young leaves remain very small You may also notice interveinal chlorosis which occurs first on older leaves, then progresses to the entire plant. Molybdenum deficiencies frequently resemble nitrogen deficiencies, with older leaves chlorotic with rolled/curled margins and stunted growth. If you are adding a high nitrogen fertilizer during vegetative growth you should look for twisted younger leaves which eventually die which means it is molybdenum and not nitrogen..

Casues are usually due to pH, often with acidic soils (soils with a pH of 5.2 and below). An excess of sulfur or copper can also cause a molybdenum deficiency.

Molybdenum toxicity will cause a discoloration of leaves depending on plant species. This condition is rare but could occur. You will notice it right away after adding a fertilizer that is high in molybdenum. Since it is used by the plant in very small quantities, I would not recommend adding it. I say this not just to avoid harming your plant, there may be health effects from consumption of high amounts of molybdenum so if you are not 100% sure you have a deficiency, don’t worry about it.
Good Growing,
Dr. E.R. Myers

E-mail- Brown leaf tips

2011-10-07T16:23:00.002-05:00

I have noticed the tips of my leaves have brown tips. What does this mean and if it is a problem how can I fix it?

Thanks for your question.
Browning of leaf tips or leaf margins (leaf edges are called margins) can be caused by a few different things. The first thing I would guess being an indoor gardener is a lack of humidity. If you don’t have one, you should think about getting a thermometer with a min/max setting for temperature and humidity. I have one that takes the humidity reading on a remote wire. I like this because you can put the sensor by your plant tops near the light to be sure the temperature and humidity are in their optimal range by the plant tops, and then you can put the base by your plant pots/floor to see what the humidity and temperature are down there. If you use an HPS or MH these bulbs generate a lot of heat (which can also cause leaf tips to burn) and also reduce humidity. This low humidity can be good as low humidity is bad for spider mites (LINK) and fungal disease, but also not the best situation for your plants. If you do have low humidity (30% or less) I think this may be something (brown leaf tips) you may want to live with. You can mist your plants, have the pots sit in trays with stones and standing water and water you plants a bit more often, but all these can have negative side effects. If the brown tips do not get worst, or you do not see other leaf discoloration the best thing might be to do nothing.

Brown leaf tips and brown along the margins can also be a sign of fertilizer burn and/or poor water quality. If you are using more than the recommended amount of fertilizer the brown tips are a sign you should not add more or reduce the amount of fertilizer. If your water has high amounts of chlorine or chloramines you could consider a water filter. Lastly, if you are using an insecticidal soap this may cause brown leaf tips.
Please feel free to send me any more questions if you have them.
Good Growing,
Dr. E.R. Myers

Nutrient Basics - Copper

2011-10-01T04:28:00.000-05:00

Copper is part of many plant enzymes so it is essential for plants to have trace amounts of this nutrient.

Copper deficiencies appear in young leaves in a unique way, leaf centers yellow while veins and leaf margins remain green for a while. Shoots tips die, which is seen as leaves fail to develop. If they do grow, young leaves often become dark green and twisted. They may die back or just exhibit necrotic spots. Overall growth and yield will be deficient as well.

Causes of copper deficiencies are usually due to pH, plants grown in peat soils or given too much lime. Excess phosphorus, zinc or nitrogen can also cause a copper deficiency

As with any nutrient, copper toxicity is possible. Good Growers know copper is required only in very small amounts and readily becomes toxic in solution. Excess values will induce iron deficiency. Root growth will be stunted showing reduced branching, abnormal darkening and thickening of roots.

Good Growing,
Dr. E.R. Myers

Beneficial Microrgansim - Links to Products

2011-09-21T04:25:00.007-05:00

E-mail - What is Beneficial Bacteria?

2011-09-17T16:21:00.008-05:00

Hi Dr. I'm new to growing but have reading lots of material because this new found hobby is becoming an obsession. Through some of my reads I usually find something about what is called beneficial bacteria. This has been of interest to me ever since I've first encountered it.

What can you tell me about these beneficials and are they necessary too maintain a beautiful garden with great yields? If so is there any productyou can recommend?
Thanks for your time Doc.

Thanks for your question. I think we all have a passion for growing. Most organisms in the world, maybe all, depend on other organisms to survive. Various plant, bacteria and fungus species have evolved beneficial relationships with each other especially in the soil.. For example, fungal species have small root like projections called hypahae that can absorb nutrients out of the soil more efficiently than a plant root. However, plants due to photosynthesis can acquire sugars easier than a fungus can absorb it. So, over time several type of fungal and plant species have created a mutualistic relationship where the plants give the fungus sugar to eat, and the fungus helps the plant get nutrients out of the soil more efficiently. In fact, 90 percent of all plant species have a relationship with one or more fungi which is termed mycorrhizal (Greek for fungus roots plural form is mycorrhizae). Evidence of this relationship with plants has been seen in fossil records from over 350 million years ago. There must be a benefit for something to persisit so long.

Maybe the best example of a mutualistic relationship between fungus and plants is with orchids. A lot of people like to grow orchids, but it is not easy to do. Many orchids need to have a specific species of fungus in the soil/medium where the seeds germinate and around the roots in order to germinate and grow. If an orchid breeder does not have the correct fungus (Mycorrhizae) than the orchid seeds will not survive to adulthood no matter how optimal the environment is. Orchids are very particular plants; most plants can grow fine without mycorrhizae if you make sure the pH is in the right range and you provide all nutrients in the optimal amounts in the fertilizer… I may be lazy but I would rather let the bacterial and fungus do the work with the plant roots…

Adding beneficial microorganisms may be a very important way to provide optimal nutrients with organic growing. With organic gardening you want to create an environment in the soil/medium where your plant and other organisms interact to get optimal results. I once convinced a friend to use, bat and sea bird guano to help him grow better. A week later I saw him and he came right up to me and got in my face, “My buddy said that stuff you gave me will get bacteria growing in my pots!”
I laughed and said, “I bet it will”
He seemed shocked, expecting me to deny it, or defend against his verbal onslaught. I explained that when growing organically, you want to cultivate bacteria in the soil. Bacteria are important in recycling and supplying nutrients to plants. There are thousands of beneficial bacteria species, some types of bacteria fix elements such as nitrogen, while the plants supply the bacteria with sugar (food) and a place to live. Many plants in the legume or bean family have little nodules (bumps) on their roots that provide a place to live for the bacteria. The bacteria get room and board and their waste product is nitrogen, which is usually the most limiting nutrient to plant growth. Something outdoor growers might want to know is that for centuries many cultures of people have planted legumes like beans, peas, clover, alfalfa etc. in their fields after harvesting their crops to add organic nitrogen for next years crops. If you later till (mix) the plants into the soil, that is called a green manure and will add nitrogen and organic matter to the soil, a great way to build up the soil for most plants. You could throw some clover or alfalfa seeds down after you harvest your plants and them mix those plants into the ground in the spring before you plant your crop.

Bacteria are also important to plant growth because when bacteria find organic material to digest they secrete enzymes to dissolve whatever it is they are metabolizing. These enzymes benefit plants by making nutrients available that without the bacteria would not be. Lastly, bacteria can also be used to fight off insect attack. The only organic insecticide called BT is actually derived from a bacterium named Bacillus thurengiensis, a close relative to anthrax. This bacteria makes an insecticide that is widely used as an organic insecticide. Not only that but the gene that makes this insecticide has been inserted into most crop species so that the plants make the insecticide themselves, and don’t need to be sprayed with petrochemicals during the growing season.

I have written more about beneficial bacteria(LINK to post with products that have beneficials) and will be testing some products such as roots organics by Auroa to see how these beneficial microorganism help plant growth, stay tuned…

Good Growing,
Dr. E.R. Myers

Nutrient Basics - Boron

2011-09-12T16:22:00.000-05:00

Boron has biochemical functions that are not yet fully determined It is involved with root, fruit and seed formation andevidence suggests it is involved in the synthesis of one of the bases for the nucleic acid (RNA uracil) formation.

A Boron deficiency will have plants that exhibit corky spots on fruit. Rust-coloured cracks develop in stems and leafstalks, which later develop a corky edge. Leaves become thick, leathery, discoloured. Plants fail to bloom. One of the earliest symptoms is failure of root tips to elongate normally which would be obvious to hydroponic growers more so than soil growers. Root tips often become swollen and discolored.

Soils high in calcium or potassium can lead to boron deficiencies.

Boron Toxicity will result in yellowing of leaf tips followed by necrosis of the leaves beginning at tips or margins and progressing inward eventually leaves die and prematurely fall off. Some plant species are especially sensitive to boron accumulation.

Good Growing,
Dr E.R. Myers

E-mail - Nutrient Deficiency and other aeroponic problems

2011-09-05T16:20:00.002-05:00

Hello Doc,
My plants have purple on the stems and in the veins of the leafs but just at he top -- also the plant is wilting hanging down what can I do to fix this? I'm using a aerogarden and they have been known to cause stem rot I got stem rot on all plants so I added dirt around the stem past the rot and I also have been turning the pump off to keep the soil moist will this stem rot go away will the plant root up to where I burried it to?

You have a few problems my friend. The purple may be due to phosphorus deficiencies, do your plants exhibit slow growth with weak and stunted plants? Is the purple pigmentation in older leaves and stems? On the other hand, excess potassium can aggravate the uptake of magnesium, manganese, zinc and iron and effect the availability of calcium and can lead to purple coloration in some plants. Only you know if you are giving too much potasium or not enough phosphorus. With non-soil growth the pH can get too high or low and make nutrients unavailable to plants even if you include them in your fertizer. How often do you check the pH?

The wilting of plants is never good. Either the plants are getting too much water or not enough - in your case I’d say the plants are getting too much water, or really too little oxygen. Plant roots absorb water for the plant, but they also need access to oxygen, which most land plants can not get if the soil or medium is always saturated with water. Reducing the time the water is on is a good idea, you want the roots to be wet but not drenched all the time.
Putting soil around the stem rot may be a bad idea. You want the stems to dry out. You may be keeping the stems wet by putting dirt around them! You need to increase air flow and try to keep the stems dry. Put a small fan on your plants and run the pump periodically, say for 1/2 hour every 2-3 hours.(or whatever the lowest setting is) This would allow the stems to dry and prevent rot. Is it possible for you to find a stem rot resistant variety to grow in your system for next time? Look into it.

Good Growing,
Dr. E.R. Myers

Nutrient Basics - Manganese

2011-08-30T04:23:00.001-05:00

Manganese plays a structural role in the chloroplast membrane system, and also is important in numerous enzymes allowing them to work properly.

A manganese deficiency is difficult to diagnose since it resembles an iron deficiency. Yellowing (chlorosis) is most severe at the top of the plant. Yellowing of the leaves appears first near leaf margins and develops in a V-shaped pattern. Leaves then develop tan or gray spots that can easily be mistaken for air pollution damage. These spots are the major difference between manganese and iron deficiency.

Good growers know manganese gets locked out when the pH is too high, and when there's too much iron. Use chelated Mn if you have a deficiency.

Causes of manganese deficiencies are soils with a high pH (Alkaline), soils high in humus or peaty soils.

Manganese Toxicity appears as chlorosis, or blotchy leaf tissue due to insufficient chlorophyll synthesis. Growth rate will slow and vigor will decline.

Good Growing,
Dr. E.R. Myers

Nutrient Basics - Iron

2011-08-20T16:26:00.003-05:00

Iron is an important component of some plant enzymes so while it is needed in small amounts, if it is deficinet you will not gave the best growth you can bet.

With an iron (Fe) deficiency like all movable nutrient deficiencies you will notice the change at the top of the plant as it works its way down. With an Iron deficiency look for the leaves to turn yellow but retain green veins. Shoots may die back and fruit may be discolored.

Causes of iron deficines are alkaline soil, (i.e. basic sols that are way above 7.0), applying too much phosphorus, over watering *The number one problem people have when E-mailing me*, excessive soluble salts, inadequate drainage. The good news, this is easily corrected by adding an iron supplement with the next watering.

Good growers know iron is unavailable to plants when the pH of the water or soil is too high. If iron appears to be deficient, lower the pH to about 6.5 (for rockwool, about 5.7), and check that you're not adding too much phosphorus, which as I said above can lock up iron. Use iron that's chelated for maximum availability. Read your fertilizer's ingredients - chelated iron might read something like "iron EDTA". Keep in mind too much iron without adding enough P can cause a P-deficiency.

You should also know that when adding iron to the solution, it is often necessary to not use fertilizer for that watering. Iron has a tendency of reacting with many of the components of fertilizer solutions, and will cause nutrient lockup to occur. Read the labels of both the iron supplement and the fertilizer you are using before you attempt to combine the two.

Iron Toxicity is rare but could cause brown spots on leaf surface.

Good Growing,
Dr. E.R. Myers

Nutrient Basics - Sulfur

2011-08-13T16:21:00.001-05:00

Sulfur or sulfate is involved in protein synthesis. It is important in plant metabolism and involved with synthesis and breakdown of fatty acids.

A Sulfur deficiency looks like a nitrogen deficiency accept it shows up in the young leaves first. The young leaves will show yellowing of the entire leaf including veins but usually do not dry out. Also, you may notice the stems are weak. You may notice the leaf tips may yellow and curl downward. Some plants may show purple at the tips of the branches. Purple color is normal in some plant varieties but not usually just at the growing tip.

Causes of Sulfur deficiency are very wet or sandy soils or when soils contain an excess of nitrogen

As with any nutrient too much is just as bad as too little sulfur toxicity will show up with leaf size being reduced and overall growth will be stunted. You will also notice leaves yellowing or scorched at the edges. Excess sulfur may cause early senescence (when plants begin to die back for the winter)

Good Growing,
Dr. E.R. Myers

Nutrient Basics - Calcium

2011-08-06T16:24:00.004-05:00

Calcium plays an important role at the cellular and molecular level in plants. This means it helps plant cells to function properly.

Symptoms of Calcium Deficiencies - first appear in new growth. Young leaves are affected first and become small and/or chlorotic (yellow or white to yellow) with irregular margins, spotting or necrotic areas. Chlorosis begins first at leaf edges then moves in. You may also notice young leaves become crinkled. Stem shoots stop growing and thicken and terminal buds become distorted. For indoor growers you should first rule out heat stress as a cause of the symptoms which has the same symptoms. You can tell if the problems are do to heat stress because this damage occurs only at the tops of the plants closest to the lamps. If you have a calcium deficiency the tips of all branches (not just the branches at the top of the plant by the light) will show symptoms. There's only one cure for heat stress problems...get the heat away from the plants, either by moving the lamps or moving the plants.

Causes of calcium deficiencies are acid soils/grow mediums, sandy soils. Soils that contain an excess of magnesium or potassium can cause calcium problems too. Temporary calcium problems may be due to drought or excess moisture but this should not be a problem indoors.

Good growers will look for calcium as a micronutrient in fertilizers; it is not in all fertilizers. Organic sources of calcium are eggshells. I put egg shells in my compost to ensure the compost has calcium in it. And. if you like seafood or live by the ocean you might have access to oyster shells. You can grind or break these up and soak them in water you plan to use to water your plants with. You could even add some shell pieces to the hydroponic resevoir or soil.

Good Growing,
Dr. E.R. Myers

E-mail LED's and Clones/Cuttings

2011-08-01T04:28:00.003-05:00

Hey I just placed a full order form you guys this morning and can’t wait till it gets here! I was wondering, can I use the 120w LED Starship during the cloning phase or should I use something else?.

Thanks,

I have posted on the blog about using LED’s for seedlings and flowering. I have had good success with LED’s for, cloning, vegetative and flowering. One word of caution however, I have had quite a few people write about how the LED”s have burnt their plants. These people used the LED's incorrectly and had them a few inches above their plants. See my post on light height. This ‘burnt plant’ problem is not due to heat but from light intensity actually. The LED’s from HTGSupply.com are so intense they can cause the plant pigments to become overwhelmed with light. This will stop photosynthesis and can destroy plant tissue. I would not recommend an LED be closer than one foot above plants and maybe even two feet depending on the plants you are growing. With clones, I would actually recommend keeping the LED three feet above the plants. I say this because with clones, you want a lower light source since they lack roots and an intense light will cause the cuts to use up water in their cells to do photosynthesis. With cuttings you want to have a warm, humid environment and a low light source to maximize success.

Good Growing,
Dr .E.R. Myers

Lower Leaf Symptoms (MOBILE NUTRIENTS) – Wrap up

2011-07-26T16:23:00.003-05:00

I have listed below links to the posts that involve mobile elements. Mobile elements are more likely to exhibit visual deficiencies in the older leaves, because when these nutrients are limited they will be exported from the older leaves to the new growth. You will see the problems first on the lower leaves as the nutrients are moved to the newer fast growing leaves at the top of the plant. So, when you see symptoms develop on lower leaves, read the posts for these nutrients and see if one is lacking.

Nitrogen

Phosphorus

Potassium

Magnesium

Zinc

The immobile elements will be written about in Aug.
Good Growing,
Dr. E.R. Myers

Nutrient Basics -- Zinc

2011-07-21T16:20:00.002-05:00

Zinc plays a roll in the same enzyme functions as manganese and magnesium. More than eighty enzymes contain zinc. Zinc participates in chlorophyll formation and helps prevent chlorophyll destruction. This means zinc deficiencies look similar to nitrogen deficiency with rolled leaf margin. Chlorosis shows up first in young leaves, which are also reduced in size. Zinc deficiency may also produce "rosetting"; the stem fails to elongate behind the growing tip, so that the terminal leaves become tightly bunched. Zinc deficiencies appear as chlorosis in the inter-veinal areas of new leaves Zinc deficiency produces "little leaf" in many species, especially woody ones; the younger leaves are distinctly smaller than normal

Zinc also gets locked out due to high pH. Zn, Fe, and Mn deficiencies often occur together, and are usually from a high pH. Don't overdo the micro-nutrients- lower the pH if that's the problem so the nutrients become available. Too much zinc is toxic. Foliar feed if the plant looks real bad. Use chelated zinc.

Zinc toxicity can occur when adding too much zinc and in soils excessively high in phosphates, nitrogen, calcium, or aluminium. Excess Zinc is extremely toxic and will cause rapid death. Excess zinc interferes with iron causing chlorosis from iron deficiency. Excess will cause sensitive plants to become chlorotic.

Good Growing,
Dr. E.R. Myers

Nutrient Basics -- Magnesium

2011-07-16T16:22:00.012-05:00

Magnesium (Mg) is vital for photosynthesis since it is a part of the chlorophyll molecule. When you add Mg the plants will become a dark green. Magnesium is important also because it facilitates the use of nitrogen, phosphorus and sulfur. Also, Mg is needed in the formation of some plant proteins.

Signs of a Magnesium Deficiency -- For most plants a Mg deficiency first shows up in the lower leaves as discoloring in the veins. They first turn yellow, then orange and finally brown. Plant leaves will feel thin, brittle and sometimes cup upward.

Causes of a Magnesium Deficiency – soils that are too wet, (if growing in soil the top of the soil in the pot should be dry before watering.) Low pH (acidic) or soils high in peat or sand. Moreover, soils given a high concentration of potash fertilizers or calcium can also show signs of an Mg deficiency. Mg can get locked-up by too much chlorine or ammonium nitrogen. Keep in mind you do not want to overdo Mg or you'll lock up other nutrients.

Cures for a Magnesium Deficiency -- Epsom salt is a cheap way to add Mg, using one table spoon per gallon once a month should suffice. Also, dolomite lime will add Mg, Calcium and keep the pH in a good range for most plant growth. When mixing up soil, use at least 2 teaspoon dolomite lime per gallon of soil. I use twice that personally.
For a quick correction of an Mg deficiency you can foliar fed the plants with ½ teaspoon/quart of Epsom salts (first dissolved in some hot water).
If your water is above 200 ppm, the hard water may lock out Mg with all of the calcium in the water. Either add a 1/4 teaspoon per gallon of Epsom salts or lime or invest in a water filter from HTGSupply.com (LINK to water filters).

Good Growing,
Dr. E.R. Myers

Nutrient Basics -- Potassium

2011-07-10T16:22:00.002-05:00

Potassium (K) is important for the formation of flowers, fruit, and leaves. It also helps photosynthesis at low light levels and in internal water regulation. I have read it improves flavor in fruit, vegetables and flower color. Potassium is also linked to insect damage protection, disease and frost protection. Lack of potassium will reduce yield and quality.

Signs of a Potassium Deficiency --Older leaves are initially chlorotic becoming mottled or spotted, root systems are poorly developed and, fruit ripens unevenly. These symptoms will first apparent on the tips and margins (edges) of the leaves. Stem and branches may become weak and easily broken, the plant may also stretch. The plant will become susceptible to disease and toxicity. Also, a potassium deficiency will result in poor storage qualities (storage of herbs link)

Potassium can be limited in plants by too much sodium (Na) which displaces potassium, causing a deficiency. Sources of high salinity are: baking soda (sodium bicarbonate "pH-up"), too much manure, and the use of water-softening filters (which should not be used). If the problem is Na, flush the soil. K can get locked up from too much Ca or ammonium nitrogen, and possibly cold weather/ temperatures.

Organic sources of potassium are kelp or any seaweed and wood ash. Potassium toxicity is rare so make sure to give plants potassium in all stages of growth. I do not like to use fertilizers that lack potassium as the sole source of nutrients.

Good Growing,
Dr. E. R. Myers

Nutrient Basics - Phosphorus

2011-07-04T16:20:00.002-05:00

Happy Independence Day!

Phosphorus (P) is also a vital nutrient for all plants that needs to be available to plants in all stages of growth. Phosphorus is the second number in fertilizers, so that a 5-15-5 fertilize would be 15% phosphorus. Specifically, phosphorus is crucial in root formation, flowering, fruiting and ripening. So, you should provide your plants with a fertilizer that has the middle number as the highest when you have seedlings, newly rooted cuttings, and from beginning to end during flowering/fruiting.

Signs of a Phosphorus Deficiency -- Early in the deficiency, plants look almost too healthy with what appears to be normal but undersized plants with dark green leaves. However, you may notice the leaves and or their veins and leaf stems (called petioles) frequently changing to purple, especially the undersides of leaves. Leaves may curl under with some plants. Sometimes the leaves will turn a gray brown with a phosphorus deficiency and you may mistake this for a fungal infestation. Look for the color change to be at the leaf tips with a phosphorus deficiency where as a fungal infestation will be all over the leaf in a more random pattern. Fungi can develop when water is allowed to remain on the leaves if you mist your plants or they are growing outdoors. Cold water can also be a cause of spotting. Use room temperature water when watering and misting. You will notice very poor flowering and fruiting if you have a phosphorus deficiency.

Phosphorus Deficiency – can occur in cold, wet or very acidic (below pH5) soils; also very alkaline soils (above pH 7.3). You will need to adjust the pH if it is below 5 or above 7.3 since no matter how much fertilizer you add it won’t be available to plants at those extreme pH’s. You should also consider potting up your plants with a pH problem the new soil will be a quick fix but you should still adjust the pH so the problem does not come back.

Bone meal is a good organic source of phosphorus and you can add this to a soil mix.

Good Growing
Dr. E.R. Myers

Nutrient Basics – Nitrogen

2011-07-01T04:22:00.002-05:00

After reading this post, be sure to see how different forms of nitrogen affect pH (LINK)
Nitrogen (N) is a vital nutrient for all plants and it should be made available to plants in all stages of growth, although it should be given in lesser amounts during flowering. It is always listed as a percentage of every fertilizer as the first number. For example, a fertilizer listed as 5-1-2 would contain 5% nitrogen. Nitrogen is needed in all organisms as part of their DNA, it is also needed in many enzymes which regulate all metabolic activity in plant cells. Nitrogen will promote increases in stem and leaf growth and causes leaves to have dark green growth.

Sign of a Nitrogen Deficiency -- Plants will exhibit slow growth and will be stunted. If the problem is not corrected yield will be significantly reduced. The first thing you will notice is that older leaves become yellow (chlorotic). Nitrogen deficient plants will exhibit uniform light green to yellow color on older leaves, these leaves may die and drop. This color change will begin at the tips of leaves at the bottom of plant especially older leaves and the color change / yellowing gradually spreads up the plant to the top. Please note that many plants will exhibit these symptoms during flowering which is normal.

Nitrogen Deficiency Causes -- You can get a deficiency in fast growing crops, so if you are growing a plant that grows fast feed it a lot of nitrogen (never more than recommended by the manufacture!). You will also get a deficiency if you grow in very sandy soils (sand promotes good drainage but holds no nutrients for plants) or if you grow plants in soils with low in organic material (See compost link). Also, excessively wet soils and high or low pH can cause nitrogen deficiency. After you check the pH and adjust it to your plants optimal pH you can add Nitrogen fertilizer. The actual number is not so important as making sure the first number is the highest.

Nitrogen Toxicity is possible, so never over do it! With nitrogen toxicity leaves are often dark green and in the early stages plants are abundant with foliage. Eventually leaves will dry and begin to fall off. If you think you killed your plants by over doing nitrogen check and see if the root system is under developed or deteriorated, this is a sure sign you added too much nitrogen.

Organic sources of nitrogen are best in my opinion, you can get nitrogen in blood meal, most guanos manures and for free in urine. One cup of urine per gallon is a free source of nitrogen.

Remember though that if you are going to flower or fruit your plants you want to reduce the nitrogen percentage and have phosphorus (the second number in fertilizers) be the highest… Too much nitrogen delays flowering. Plants should be allowed to become ALMOST nitrogen-deficient late in flowering so that it does not inhibit flowering and I have read low nitrogen late in flowering can increase fruit flavor.

Good Growing,
Dr. E.R. Myers

Setting up a closet grow space -1

2011-06-27T04:22:00.001-05:00

I have written about setting up a grow space before (Set up 1 and Set up 2 and Set up 3)

The first ting you should do I think is put plastic down on the floor if you are going to grow indoors. I like to use a closet so that I can control the light cycle. You can also use a grow tent if you don’t have a spare closet. However, my main grow area at my college is open to the sky via windors/skylights and I use a 600 W HPS as supplemental light for my tropical plants. No matter what light cycle I put the 600 W light on the plants follow the suns cycle. After you put down the plastic you should go inside your grow area and look for light leaks…. Tiny little holes. Wait a minute or three with the door closed for your eyes to adjust and then look for any light leaks. You can take a marker in with you and mark where you see light and then seal the area better where the marks are.

The reason you need plastic is because plants need water, and growing indoors means you have to water them and humans make mistakes (water will spill). Water in carpet like I am showing here will 1) stain the carpet and more importantly 2) can lead to mold growth. Neither is recommending for good growing.

Measure the closet or grow area and if there are walls (you are not growing in the middle of a room for example) then add an inch or two to the length and width. You will want some over lap so that you can tape the plastic to the wall. You do NOT want the plastic to be a few inches short since this can mean dirt and water can get under the plastic to make a great environment for mold growth.

Once you have plastic on the floor and have checked for light leaks, it is time to hang electrical stuff above plants if possible. I hope everyone knows water and electricity do not mix.

Good Growing

Dr. E.R. Myers

Germinating Media

2011-06-15T16:23:00.001-05:00

In a previous post I compared a soil mixture to rockwool and starter plugs to see which was the best for germination. I found my soil mix was the best, but I really like and use the starter plugs a lot. Here I continue looking at seed germination.
Please read my post on how to speed up germination too
Growing Media, or Germinating Media is plural for Growing Medium or Germinating Medium, This is the material in which the seed is placed to germinate and begin to grow. Of the various growing media, you will need to select the medium that is best for your specific plant and growing environment.
Listed here are some of the options that are widely available for the gardener.

Vermiculite is expanded mica. It can retain a large volume of water for long periods of time. Although it contains a high level of magnesium and potassium and can hold nutrients and is good for aeration, it is not often used by itself I would sugges mixing it with perilite or soil in a final mixture for germinating seeds.

Perilite is a volcanic glass. It holds water on its surface but does not allow much absorption. It has no elements needed for plant growth and does not hold nutrients well. It does promote good aeration , stays cool and is a very good ingredient as part of a growing or germination medium.

Sand can be a good choice for root cuttings but is a bit too heavy for germinating seeds and can dry out quickly since it does not hold water, nor nutrients. I would not recommend it for germinating seeds but I do add it to most of my soil mixes to promote aeration.

Garden soil can be good for plants to grow in but in most areas will not offer the optimal conditions for germinating seeds because it does not allow for proper aeration and drainage for seeds. Also, it is not sterile. You can sterilization it (bake it in a pan at 300 degrees for 30 minutes) but I would suggest you sue a soil mix from HTGSupply.com with vermiculate, perlite, peat moss etc. to germinate seeds. There are many seed germination mixes available from HTGSupply.com where the work of mixing has been done for you.

Starter plugs – my favorite medium for germination at the moment is the starter plugs. They are made from tree bark provide some nutrients to the seedlings and are low mess and make transplanting easy.

Good Growing,
Dr. E.R. Myers

Grow Methods- Using a Screen

2011-06-07T16:23:00.003-05:00

Please be sure to see my second post about using a screen after you read this....
You can increase the growth area by training your plants, this can be good if growing in small spaces.
You can use a screen to maximze plant growth, especially in areas with a low height. The screen should be set about 1-2 feet above the planting medium, if possible. There are two purposes for that gap. First, you have to get your hands underneath the screen in order to handle the plant shoots and to water the plants. Second, there needs to be sufficient space for the plant to branch. Branching is essential to Screen training. Some growers prefer shorter gaps for smaller lights, as little as 4-6" between screen and plants when using fluorescent lights is ok.
Note that the screen does not have to be absolutely flat, and there are good arguments for bending the screen to match the curvature of the light field. I think most growers have tall plants on the outer edge of the grow area and shorter plants in the middle so you can set your screen up like this if you wish.
This type of method of growth is great for clones. Clones are set under the screen at a density of about 1 plant per sq. ft. Experience in using the method with various types of plants may result in more or fewer plants, but 1 per ft. is a good starting point. Note that plant density is much lower than for a normal or more traditional plant growth method That means fewer clones to manage and fewer plants to be cloned. One 8 site clone bucket could supply you with all the clones you need.
The clones are established and kept on 24 hrs or 18/6 until they show new vegetative growth. About the time where the growing tips penetrate a few inches above the screen, say at two weeks, the lights are switched to a 12 hour dark period if you are growing plants that produce in the fall. The plants will continue to grow, filling the screen with growth. At a density of 1 plant per ft., it usually works out that the plants stop and "crown off" just as the screen is filled. Note that this timing method is not universal. Different plants may require more vegetative growth, or perhaps even less. My advice is to start by flowering asap the first time, because overgrowth of plants will not increase yields.
Training really isn't difficult. With a limber plant I usually let the shoots grow vertically above the screen and then pull and bend them under the wire re-orienting the stem horizontally under the screen to line up bud/flower sites with screen holes. You don't have to tie anything down, as the upward pressure of the stem will hold the foliage to the screen, but some growers like to tie off stems to the screen during the early phases of screen filling.
Some plants have brittle stems, and are difficult to train. It is possible to bend a stem by crushing it lightly at the bend. So long as the vessels in the plant that carry fluids aren't damaged too much, the shoot will heal and be just. It may also be possible to top brittle plants under the screen, so that the future growth will be in several, more slender shoots.
The second pruning step occurs during and after the screen is filled. All growth under the screen must now be clipped off. Shaded growth quickly shrivels and dies, leaving ideal growth mediums for mold. Excess leaves and shoots should be clipped close to the stem, to avoid leaving stumps as mold sites. Subsequent pruning is really limited once the plant starts flowering and stops growing.

Click here to see my second post about using a screen....

Good Growing
Dr. E.R. Myers

E-mail - The Standards Questions about LED's

2011-06-01T04:21:00.001-05:00

Good Afternoon Doc,
Perhaps you can help me. I am considering starting an indoor organic garden. I hear many sides to these new LED systems being more efficient in power and yields. I am considering buying your recommended 300 Watt High Powered Tri-Band LED Grow Light. How does it compare to this 357 Magnum LED who claims he has 119 x 3W Bridgelux Diodes that only consume "180W" and are superior to any other LED system on the market. Why does this sound so ridicules and how is it possible so many people say conflicting statements? The companies are like children bashing each others' claims. I tried doing sufficient research but have been unable to find a superior legitimate LED growing system for a plant's complete life cycle. Are there transformers out there changing the game? What makes one different from the other. What are the most important features to look for?
Another grower says the 4 wavelengths is old technology.
Can you please give me your honest non-biased input. I am considering growing in a 4x4 area in a dark corner of a room.

Hi,

As you may know, plants absorb light energy in certain wavelengths. To put it simply, wavelengths are seen by humans as colors, and the two most important colors (and indeed essential for growth) are red and blue wavelengths. These wavelengths are measured in nanometers (nm). HOWEVER, what we see as red, is not always in the exact best wavelength for plants to use. For example, if a plant absorbs red at 660nm and that makes it grow the best, our eyes would not be able to tell if a red LED was really 650nm or 670nm. Here is some important information, the cheapest LED’s are one’s that don't work as well or at all for plant growth because the emit what looks red to our eyes but is not the actual wavelength that is best for plants.
The problem, or benefit of LED"s is that they can emit light in such a specific wavelength, where as an HPS or MH emits light in all the wavelengths from red to yellow orange blue etc.. This means if you get the RIGHT LED you are saving energy by only using only the optimal wavelength of red, where as if you get the WRONG, CHEAP LED you are wasting time by not growing plants in the best environment.
I have never had the opportunity to test any of the lights, other than the one's you mentioned from HTGSupply.com. I do know all Tri-Band lights work great in all stages of plant growth, I have shown this in many blog posts. The Tri-Bands are emitting red and blue in the RIGHT wavelength. You might be able to get by with the 120W starship light, but the 300W will be good for a 4x4 area.
Good Growing,
Dr. E.R. Myers

E-mail – New Light on Too Long During Flowering

2011-05-26T16:23:00.003-05:00

Hey Doc,
I made a big mistake and I was wondering if I can do anything to fix it. I added a 120 W LED to my grow area which had a 400 W HPS, in order to increase the number of plants and the yield of plants. However, I only had the HPS on a timer, the LED was on 24hrs a day. I had a multiple outlet extension cord and instead of having the extension cord on a timer I just had one light. This happened for a week in about the third week of flowering. The plants have slowed their flowering. Any help would be great.

Well, other than a time machine there is not much you can do. The plants should recover and start flowering again, but you will definitely need more time than normal until the flowers/fruit are done. Keep the plants on 12/12 until they are done. If you are growing male or female plants you will also have to watch for the plants to become hermaphrodites. Sorry I can’t be more help. I will post this on the blog as a lessoned learned

Good Growing
Dr. E.R. Myers

Get Ready for Outdoor Growing III Hardening off

2011-05-16T16:27:00.000-05:00

Please see my post on hardening off, before you move your plants from their indoor grow area to the outdoors, it could save you a lot of hassle and increase yields.

Although it sounds silly, plants that are grown indoors are not able to handle the sun. Sure I have said the sun is the best source of energy for plants (intense and free). However, the indoor lights you get from HTGSupply.com are great for growing, but they don't have UV radiation like the sun, or all the other types of energy that come from the sun. You need to gradually get your plants used to the intense UV and other types of energy that are part of the light energy plants need that comes from the sun. You should do this over a few days so that they are not stressed out and grow slowly, or even die.

How to get your plants ready for the sun.

Good Growing,
Dr. E.R. Myers

Get Ready for Outdoor Growing II SOIL

2011-05-11T16:22:00.001-05:00

Once you start your seeds you need to make sure the soil where you are going to grow your plants is suitable. If not there are countless soil amendments from HTGSupply.com that can make sure your outdoor garden thrives as well as your indoor.

First thing I would do is see what your soil is made up of. Basically soil is made up of four things, sand, silt clay and organic matter. An easy way to test this is to get an empty olive or pickle jar, put some soil from where you will grow in the jar about 1/3 full, put a drop of dish soap in the jar (to help particles separate) and then fill the jar to the ¾ mark with tap water. Put on the lid and shake vigorously. Let the jar sit over night.

In the am, you should notice different layers. The bottom layer will be sand, the middle silt and the top whitish layer is clay. You may have small bits of ‘things’ on top of the clay, that is organic matter. Also, if the water above the soil is dark like tea, that too means you have some organic matter. Measure the total height of the dirt, then divide the total height by the height of each type of particle. The number you get is the percentage of each particle type

EXAMPLE. You have 6 inches of total soil. If you have 4 inches of sand, 1.5 inches of silt and 0.5 inches of clay you divided 4/6 and 1.5/6 and 0.5/6 you have 66.6% sand, 25% silt and 8% clay. This soil would need Coir or some other form of organic matter like compost.
I say this because if you have mostly sand the soil will tend to dry out so you will want to increase water retention. If you have mostly clay, you could add organic matter like coir which helps drainage, but you can also add sand, perlite or vermiculite. With clay (also called heavy soils) you need to increase drainage and help the roots to grow. If you have near equal parts of sand and clay with some organic matter, you are ready to plant as is.

Another really cheap soil amendment is lime. You can get a 50lb bag for a few dollars and it makes the soil pH great for plants and will add Ca and Mg too.

Good Growing
Dr. E.R. Myers

Get Ready for Ourdoor Growing - I Starting Seeds

2011-05-07T04:26:00.001-05:00

There is an article about extending the growing season outdoors with your indoor hobby under "education pages" on HTGSupply.com's web page, but I want to expand on it in the next few posts as we prepare and plant our outdoor gardens.
We all love to grow indoors, but there is no better light source than the sun, no deeper pot than the soil, and no cheaper water than rain. Why not expand your indoor hobby outdoors?

First, what you want to do is start a lot of seeds. I really like the starter plugs, they are environmentally friendly (made from composted tree bark which is renewable) they have a preformed hole for your seeds and don't have the pH problems of Rockwool. They are a lot cleaner than dirt and have some nutrients in them so they get your seedlings off to a great start. Also, they make potting up a snap, with minimal root damage. You just push the plug up from the bottom and plop it into a bigger pot or into your outdoor garden, simple as that. It is a good idea to apply some fertilizer after potting up.
Next, read my post on ways to speed up the growth cycle starting with seedlings.
Good Growing,
Dr. E.R. Myers

E-mail - Flowering with Different Sized (Height) Plants

2011-05-01T04:20:00.001-05:00

Hello Dr. Myers,
I am using the T5 4bulb 2,000 Lumen that I purchased from HTGSupply.com , in the flowering stage I have 1 plant that is 2 feet taller then the others and it is too thick to really bend it. If I have the light that much higher I know the other plants arent getting enough or will take longer to flower etc.
Is there a way to relocate the other plant someplace or set it to the side, stop the flowering and then restart the flowering later?

Hello,
You have a few options.
You could try to just bend the very top of the plant if it is possible, this will stop vertical growth even if you just bend the top couple nodes... Be careful not to break the top off. If you have a two foot difference this might not solve your problem now, but in the future if this begins to happen, bend the plant that is growing taller to keep it around the same height as the others... use this as a learning experience.

Second, you could hang the light at an angle, lower on the end with the short plants, taller over the high plant so that it is as close as possible to all plants. Third, you could try putting the tall plant on its side, this will take up a lot of horizontal room, and may make watering it a hassle, but will allow you to keep the light close to all plants. What might be easiest, you could put blocks or some sturdy object UNDER the short plants to raise them to the height of the tall plant, and then remove the blocks as the other plants grow taller.
You could also try a new trick I am working on. If you are EARLY into flowering, you could cut the top 4-5 nodes off the plant and turn the plant top into a clone. You know it is the type of flower you want already so this way you'd turn one tall plant into two plants. If you are more than a few weeks into flowering, you might not have success with the clone, and just end up cutting the top of your plant off, which will also solve your height problem, but not in a good way.
You could also do as you said, move the tall plant somewhere else, put it back on 18 hrs light and give it a good dose of high N fertilizer to get it back into vegetative. However, it will start to grow tall again if you do this, so you may need to put it on its side when you flower it again, or turn it into a mother plant and put its clones in your flowering area.

I hope one of these works for you!
Good Growing
Dr. E.R. Myers

E-mail - New Light for a Small Closet

2011-04-20T16:20:00.001-05:00

Hi Doc

I’m a new grower I’m using simple 4' fluorescents right now to get my plants going, but i want to get a better light to finish veg. and flowering stages. I ont want to spend a whole lot of money. My grow room closet is small 3 1/2' by 4 1/2'with just 2 plants for now. Can you tell me what kind of light cpf/hps or mh and what watt would Be best for over all growth and flowering for the best price.

Hi, I too started out with the 4’ shop lights, they work but you will see a world of difference if you move up to a 250 watt HPS. (I think the single best light to use is an HPS) If you have a tall closet, you could use a 400 W hps, or if you are willing to vent the heat out of the closet.

You can always try a Tri-Band LED from HTGSupply.com too. If you only want to grow two plants, a 90 W UFO LED will be fine, you can use a 120W or 300W if you want to grow more plants.

If you do go with the HPS, I”d still start the plants under your fluorescent lights for 2-3 weeks, then switch to the HPS. You will notice that most plants tend to stretch (grow tall with long space between nodes) when they are placed under an HPS (this is due to the excess of red and yellow light). So you should also get some ties to tie down your plants. Simply bend over the tops a bit (careful not to break off the top) this will keep your plants from growing too tall with long internodes, and will have promote bushy growth.

Good Growing,
Dr. E.R. Myers

Test for the Best Medium for Seed Germination

2011-04-16T16:26:00.001-05:00

I did a little comparison of seed germination between three mediums: soil, Rockwool and seed starter plugs. Years ago, I always used Rockwool, I liked the lack of mess, the ease of transplanting, and ease of planting, just put a seed in the hole and you’re done. I do not like that it is not a renewable resource however. There can also be problems with pH depending on what species of plant you are growing. The seed starter plugs that are preformed have all the same benefits minus the pH problem, plus they are renewable. And of course, soil is what plants evolved to germinate in, and it is my medium of choice, with some variations so I gave that a try to.

Soil seems to be the best thing to germinate seeds in. the seeds germinated quicker, and grew as fast as either of the other two mediums. However, it is messy, and I have not tried to pot up the seedlings yet, so there is the possibility of damaging the seedlings when I try to dig them out. The Rockwool was the worst, to say the least I was disappointed. I don’t know why I liked it so much. For me this just shows you need to try new things to see if you can improve what you are doing. The germination time was about the same for all plants, but the Rockwool seedlings did not grow well compared to those in the starter plugs or soil. I think it was a pH problem as the plants just grew slower and were smaller. I think I am done with Rockwool forever. Don’t get me wrong, I am NOT giving it a thumbs down it has its uses especially in hydroponics, but I am a dirt grower for the most part. The seedlings in the starter plugs grew nearly as well as in soil, and potting up will be a snap. The only drawback to the plugs is that for plants like basil, lettuce and others with very small seeds, you may be better off with soil since the small seeds can fall down into the hole, or may not grow well if they are placed on the top of the plug. I did grow chives (small seeds) in all three mediums so you can grow plants with small seeds in plugs, but I got 1-2 plants per plug and 3-6 in the soil, so soil is more economical with small seeds. If you have not tried the seed starter plugs, give them a try.

Good Growing
Dr. E.R. Myers

E-mail - Best Fertilizers / Nutrients to Use

2011-04-09T16:22:00.005-05:00

Hello Dr. Myers,
Can you suggest suitable nutrients for vegetative and for flowering. I currently use Miracle grow with high N for veggie and high P for flowering. Do you sell something special that you have had good luck with?
Thanks in advance.

As you may know, the three numbers in a fertilizer are always nitrogen, phosphorus and potassium. For vegetative, you want the first number to by higher, like 6-5-5. The actual numbers are not as important as the ratio. For flowering, you want the second number to be the highest, like 1-5-6. (I also recommend a high middle number and a 50% dilution of high phosphorus fertilizer for seedlings since phosphorus promotes root growth as well as flowering) You also want to make sure that the nitrogen (first number) is not high when you fertilizer plants that are flowering, as high nitrogen causes plants to have reduced or no flowering. I know many growers sometimes give their plants straight water for a watering cycle or two between switching from vegetative to flowering in order to get rid of any excess nitrogen. I recommed having potassium in all stage of plant growth; it is used in a lot of metabolic processes and does not hinder any type of plant growth like nitrogen does to flowering.

I have mentioned before I hesitate to recommend specific products since each person has their own indoor environment where they grow different plants, have different grow mediums, different light sources and different amounts of CO2 and air flow. However, I really like the fox farm products, and I am using roots organics now and it also seems to be of a good quality. I have used floralicious several times (love the name) I like to recommend organic fertilizers since they often have many of the secondary or micronutrients that would be lacking in a synthetic fertilizer (like the one you are using now) that was made in a factory.

Good Growing,
Dr. E.R. Myers

Sun Soaker Reflector and Banana Tree Care

2011-04-01T04:22:00.007-05:00

I am trying to grow food in my greenhouse as a demonstration this year. I have some basil (purple plants on table) rosemary and tomatos. I have a banana tree that is almost one year old.

Notice the sunsoaker reflector overhead of the plants. I really like it since it concentrates the light in a nice 5x5 area under the reflector. I do have some suplimental sun light this time of year (Spring) so I keep it several feet above the plants to get a larger area of coverage.

Banana trees need a lot of light, but will benefit if they have a break of an hour or so from the hot afternoon sun. They will do well with a general organic fertilizer that has equal amounts of N-P-K. They like soil pH between 5.5 and 7.0. They should be well watered, but never sitting in standing water. If the top of the pot is dry to an inch or so you should water the plant, if the top is moist wait. If you are going to move them outside in summer and back in for winter in a temperate climate, watch out for spider mites, they love banana trees. As with all plants, you will need to acclimate your plants to sunlight when you first bring them outside. Always put plants outside on cloudy or rainy days for the first day, or put them in the full shade of a tree or house. After a couple days, your banana tree can tolerate the full sun.

At the end of summer if you have a smaller plant you can bring the whole plant/pot in for the winter. For larger banana trees you should cut back all of the leaves before digging up the roots. Gently brush off most of the soil from the root system and replant the trunk in a large container filled with slightly dampened soil/sand mix (50% each). Store the root ball in a warm area of your home. Don't water or fertilize at all unless the soil is very dry; you wantthe plant to go dormant for the winter. Water and fertilize well when spring comes and watch it grow.

You do not need to prune banana trees, other than for aesthetics. You should remove old brown/yellow leaves since this is a place for disease to start.

You can control how big it gets by 1) buying a dwarf variety 2) minimizing pot size and/or fertilizer.

Good Growing,
Dr. E.R. Myers

E-mail - Node Spacing Problems

2011-03-24T16:22:00.005-05:00

Hi Doc,
What deficiency causes spacing between nodes?

Do you mean long or short nodes? Long nodes can be from applying too much nitrogen or too little light, or too much heat.
Short nodes often result when the plants are in a contain that is too small (see potting up link) but can be from a phosphorus deficiency which is rare but can cause short plants. The short plants will be dark green and may turn purple (including the stems). Phosphorus is the second number in a fertilizer (N-P-K) so make sure you use a fertilizer that has phosphorus as it improves root growth in young plants, and fruit/flowering in older plants. Never use more than the manufacturers recommended dose however! Even if you are using a fertilizer with phosphorus if your pH is above 7.3 or below 5 your plants may not be able to get phosphorus so you should check your pH.

Hope this helps
Good Growing,
Dr. E.R. Myers

E-mail Set up of Filter, Reflector and Fan

2011-03-22T16:23:00.002-05:00

Hello There Doc,
I have a small grow enclosure (2x4x5) with a 400w hps air cooled reflector and a 4" inline fan for air exchange with a carbon filter. i was just wondering what the most efficient way to incorporate all these items. For example what is the best order to use these items. filter-reflector-fan. all obviously connected with 4" ducting. will this reduce the efficiency of the filter at all? and how air tight are the reflectors with a glass lens? odor and heat must be controlled. Thank you

Thanks for your E-mail. I have forwarded your question to Perry at Sales@HTGSupply.com. He is better qualified to answer questions about equipment while I answer any questions about plants and the environment you create to grow plants. If you have any biological questions please send me another E-mail
Good Growing,
Dr. E.R.Myers

From Perry at Sales@ HTGSupply.com
Hello
Thank you for your purchase. I got this question forwarded from our ASK THE DOC section. He deals with just actual growing questions and that is why he forwarded this to me.
Your idea for most efficient way to set those up is correct,” filter-reflector-fan". The manufacturers of both the filters and the fans, regardless of whom the manufacturer is, recommend having the fan at the very end pulling air threw then out the fan. Just like you mentioned! The reason being if set up so the fan is "pushing" the air through, there will be resistance from the ducting and reflector that will slow down the CFM, thus you won't get the same performance. However, if it is "pulling" at the end then out the fan, the resistance isn't as bad thus you get better performance.

Thanks again and have a nice day
Perry
Shipping Manager
www.htgsupply.com

E-mail -- Worm Castings and Soil Amendments

2011-03-17T16:25:00.002-05:00

Hello Doc,

I’m doing a soil mixture of : soil, perlite, peat moss, and worm castings. How much of each in a two gallon pot. Specifically the worm castings, a few cups each, or a few ounces each? please help.

Hi
The good news is that you can not really use too much worm castings. Many places recommend up to 10-30% of your medium consist of worm castings. You could start by adding 2 cups of castings per 1 gallon and see how the plants do with that. (There are 16 cups in a gallon so 2 cups per gallon would be 12.5% worm castings) I would also recommend using coir instead of peat moss, as coir is a renewable resource and peat moss is basically mined from wetlands. Either one can make your medium more acidic so you need to keep an eye on that. Adding some lime to your mixture (1 table spoon per gallon of medium) will help keep the pH in a good range.
Ultimately, how much of any medium amendment you use will depend on the type of plant you grow, plants that need lots of fertilizer you can use three or more cups of worm casting per gallon, plants that do not need nutrients as much you can give less.
You could also do a little experiment and give some plants more worm castings and see if you can notice a difference. That way you will know what *you* need for *your* plants.
Good growing,
Dr. E.R. Myers

Light, Photosynthesis and LED’s -- I

2011-03-11T16:28:00.001-06:00

There is some confusion about LED’s so some background information on light to get started: The first step in photosynthesis (where light energy is converted to chemical energy for the plant to use to grow and flower etc.) is the absorption of light. Pigments are any substance that absorbs visible light. No pigment can absorb all types of visible light. Visible light is also called white light since all the colors of the rainbow (red, orange, yellow, green. blue and violet) together look white to our eyes. You can see these separate colors when white light passes through a prism. A prism separates white light into colors because each color is actually a type of energy with a slightly different wavelength and so each passes thought the prism differently and separates.

Ok, now that you have the background, Plants have many pigments but the most common one is called chlorophyll, it is what makes them green since all light accept green is absorbed by chlorophyll. The light absorption pattern of a pigment is called the absorption spectrum. The absorption spectrum is not the same for all colors, it has been shown since 1800’s and again many times that red and blue are absorbed more than other colors by chlorophyll. Now this is not the end of the story… the action spectrum is the relative effectiveness of different wavelengths (colors) to elicit specific processes such as flowering or phototropism (plant moving toward light). The similarity between the absorption spectrum and the action spectrum is evidence that specific pigments are responsible for that process.

Now here is where the confusion comes with LED’s. LED’s are very efficient light sources one reason being they emit light in a very narrow band (wavelength) Light wavelengths are measured in nanometers (a nanometer is one billionth of a meter- chop up a meter stick into 1 billion equal pieces). The confusion stems from the fact the pigments in our eyes are NOT the same as the pigments in plants. So, what we see as red or blue might not be the exact wavelength, measured in nm, that is going to elicited the maximum action spectrum for plants. In other words, just because an LED looks red or blue to your eyes does not mean it is the best wavelength of light for plant growth.

This is where HTGSupply.com has done their homework. The TriBand system has been created to generate light that is in the optimal range for absorption spectrum which will lead to the maximum action spectrum (This leads to maximum growth and flowering). Here is what you need to understand… Just because two LED’s look similar (have similar shape and design) does not mean they are the same. You can have two Corvettes that have two different engines and while they look the same, they certainly won’t drive the same. HTGSupply.com created their TriBand when they began consulting me, they wanted to make an LED that was the best for plant growth. I know they grow and test plants with all their lights, and so do I (Best LED LINK -- 2nd tested LED LINK). If you are not sure about growing with an LED, I can’t speak for any other company, but I can and have seen the TriBand lights grow plants from seed to flower and I have used it for cloning, this technology works.
Good Growing,
Dr. E.R. Myers

E-mail --Confused about LED

2011-03-02T16:21:00.001-06:00

Hey there Doc,
All of this online pro and con info. has my head spinning, regarding LED grow lights. It seems that as long as the light is usable for the plants, it doesn't matter whether it comes from an LED, HPS, MH, or outer space! I need a new vegetative light and I have seen more than one positive comment about HTG Supply. I was hoping you could recommend an LED panel or UFO system that you have found effective. I will gladly order one, once my confidence has received a little boost. I need about 12 sq. feet of good intense coverage. Thanx mucho!!!

Hello,
I have done a good bit of research into LED since HTGsupply.com first contacted me. I am with you, it seems a bit confusing, and a big reason is that not all LED’s are the same. I am still an HID specifically HPS grower and LED’s don’t seem to be better than HPS for my growing needs. However, they do use less electricity (which is good) and have a lower heat output. Also, for large areas you would need multiple LED’s where as one 600W or 1000 W HPS can do the trick. This means you would spend more money on a couple-three LED’s if you have a larger area (5x5 or bigger). However, if you used 400 W of LED and compared that to 400 W HPS then I would not bet against LED’s to win. However the initial cost would be a lot more for LED, but the life of an LED is years more than an HPS so that must be figured in too…

What I can tell you is I have grown using the 120 watt tri band and I am using the new 90 UFO with 2 Watt LED bulbs and it is looking good (It has the same new Triband technology) I know LED lights are VERY popular items and have shown excellent results (LINK to UFO test).

I also used the UFO for clones (LINK CLONE BUCKET) and I had great results. I would say if you are going to use an LED, I would recommend the newer 2 watt bulbs and using the Tri-band technology from HTGSupply.com. There are a lot of other LED’s out there, but many other companies simply buy the parts from China and have no over sight or testing. I am glad to test many of HTGSupply’s stuff, and I have been happy with everything, accept the ozone generator (LINK). I know the owners care first and foremost about their customers having good products where as many other companies would rather make a quick buck and sell you a crappy product and try to find another sucker. I say go with a Tri Band LED from HTGsupply.com and you won’t need to go anywhere else.
Good Growing,
Dr. E.R.Myers

E-mail -- Looking to Increase Yields.

2011-02-23T16:25:00.002-06:00

Dr. Myers
Currently I grow bell peppers and tomatoes indoors in a scrog* type system growing hydroponically. I use 4 foot cool fluorescent shop lights which are actually producing quite a bit of veggies. However since my little 5 year old can eat more than I can produce under my current lighting I'm considering an upgrade to a 400 watt hps or MH light. What type of light is best for growing vegetables? If I get a HID light should I continue the scrog grow or grow more plants and let them grow tall? I have about a 20 by 10 foot room so how hot will a HID light heat the grow room? Also, what do you recommend for venting out through a window?

Thanks, keep up the great work on the blog.

You have the right idea, you will need to increase the light output to increase growth/yield. Also, think about growing outdoors in the summer and canning etc. to get you thru the winter months. You can't beat the sun as a light source. (and it is free)
I really like HPS lights, and they will help promote fruit/veggie/flowers. However, I am starting to like some LED’s (BEST LED and 2nd test link) The next generation of LED's that use 2 and 3 watt bulbs, they are really working great, they are beating the High Output T-5 Fluorescents which uses twice the watts!
I have not compared a scrog method to the traditional method but I know with a higher wattage HID you won’t need to use scrog. The scrog method I think is better for lower light output as it spreads out the growth under all available light. However this method is always good if you have limited vertical height. I would guess if you let plants grow taller and bigger in general, they should produce more... you want to make sure the bottoms of the plants are getting light, if you have a foot or more of bare stem at the bottom of the plant you need to increase light or keep the plants shorter. If you do go with an HPS, you should put a fan in the room to blow over the plants, the high red/yellow of the HPS promotes fruit/flowering but also can make plants stretch as they grow. A light breeze blowing over the plants will help keep plants shorter. The fan also helps control heat. If you are going to vent out a window, make sure there is a good screen, insect pests will thrive in your grow space. You will have to deal with heat a lot more with HID lights than your current set up but your room seems large enough for a 400 or 600 watt HPS. A 400 HPS is good for a 4’x4’ area and a 600 5’x5’ in general. The room may be in the 80's or 90 but should not get hotter than that unless you live in an area that has higher outside temperatures. Tomato's and peppers are tropical so while you might find 80 too hot, they will be fine. If your room gets in the high 90’s or for sure over 100 you need to vent the heat out or you will have slowed plant growth. I started growing with T-12 bulbs and I can tell you if you are doing well you will have exponential improvement even with a 250 Watt let alone a 400 watt in both yield and rate of growth. If you do go with the HPS, keep the cool white bulbs and start your plants under them for the first couple weeks of growth, as HPS can make plants especially seedlings get long and grow too tall. Tomato's need staked as it is and they will grow taller with an HPS.
Good Growing
Dr. E.R. Myers

* SCROG is The Screen of Green method of growing indoors. Basically you have a screen placed horizontally 1.5-2 feet above the plant medium and train the plants to grow in a more horizontal way by tying branches to the horizontal screen (chicken wire or other fence types are often used as the screen). This is good for growers who have limited vertical space and for growers who use lights like fluorescents that have lower light outputs since it maximizes the grow space used.

SPIDER MITES Revisited

2011-02-15T16:22:00.000-06:00

Hello Doc,
I've got spider mites and I'm struggling to get rid of them. I have been using a neem oil soap mixture and that knocks them back well enough but the problem continues to recur even after I've started preventative measures from bring any more pests into my indoor garden. All my plants are in veg stage right now. What can I do to rid myself of this problem once and for all?
Hello,
I assume you read my post about spider mites. (LINK)

I had a mite infestation and I only got rid of it at the end of the semester when I killed/harvested all my annual plants and I physically wiped every piece of the leaves and stems of plants I kept alive with a 10% alcohol solution (rubbing alcohol - isoproppyl). I also then cleaned the infested room with a 20% bleach solution and let it sit without plants for a week. I kept the light on to keep the room warm so if I missed any mites they'd starve rather than sit in the cold and wait.

What I did with the 6 plants I kept is I took each plant out of the infestation room, wiped it down in a different room, let the plant sit in the wiping room for a day until I came in the next day with new cloths etc. put the plant in a 'clean' room with a light and then went and got another plant to wipe down. This took me a week but I finally got rid of the mites. The problem is they can hide on the underside of a leaf and not get sprayed, or even on the floor or the wall or in the soil.

If you can’t wipe all your plants down after you remove them from the room your next option is to slow growth and start over with EVERYTHING new, and sterilze the room. If you want to slow growth and get a harvest Keep the humidity high and the temperature low, put double sided tape on the floor around plants and make sure plants do not touch each other as mites need to walk to get to a new plant. You could keep using the neem but you could also try and order predatory mites. These will not get rid of spider mites most likely, but will keep their numbers down so that you can harvest your plants. Then when you harvest the plants you need to wipe down the room and keep it plant free for as long as you can.
I say all this is assuming you are growing something you will consume. If you have plants just to look at, then I suggest you use a systemic insecticide that you water the plants with. This will make the plants toxic to mites (and you or any one else that consumes the plants) so it works great on plants that won't be consumed. If you have other house plants that you don't consume then you may want to give them some systemic insecticide to make sure that mites or other insect pests are not eating them and waiting for your indoor garden to get going and move back in. Keep your pets in mind when using insecticides, I don't like to use them but they work.

I am sorry to say there is no easy solution, wipe down the plants to remove mites, then get predatory mites or keep using insecticidal soap to get a harvest then start over after you clean everything with bleach, alcohol, or hydrogen peroxide.

Good Growing,
Dr. E.R. Myers

The 8 site Clone Bucket - Conclusion

2011-02-09T16:25:00.000-06:00

You can see that I got great root growth. I kept them in the bucket for a couple more weeks after I had enough roots to pot them up to see what would happen. I did start to get some leaf yellowing but I was very busy with work and did not check pH or EC so this could have easily been avoided. The 8 clone bucket can keep plants growing for a long time, I’d wager you could use it for flower plants…Or you can get 8 new clones each and every month forever, the choice is yours.

This is a great product to have for cuttings and I think it would go well with a hydroponic set up. These bare root plants / cuttings are perfect for a hydroponic system or they are ready to put into the soil or any type of medium you use. I am going to keep the plants in the bucket for a while longer and see what happens. Now that the roots are established I added some fish emulsions to the bucket (2-1-1) To make sure I had some micronutrients and I added some hydroponic fertilizer (1-5-6) to make sure root development had all the phosphorus it needed. As I have mentioned potassium is a good all around nutrient helping in most plant functions so I always choose a fertilizer that has it. It is also hard (NOT IMPOSSIBLE) to reach toxic levels of potassium so it is ok to mix two or more fertilizers that have potassium.

Good Growing,
Dr. E.R. Myers

8 Site Clone Bucket - Cuttings Taken

2011-02-02T16:22:00.000-06:00

Happy Ground Hog Day!

When you get your new 8 site clone bucket test the pump before you do anything else. First, run the pump with tap water for a few hours and then lift each one up and make sure ALL plugs are getting completely wet. If the bottom of any plug is not wet, move the pump so that the plug gets wet, dry off each plug and run the pump for a couple hours or better yet, over night and check again to make sure all the plugs are getting wet. It is very important you get the pump positioned so that all the cuttings will get water. You only need to do this one time, then the pump will stay in that position forever. I ran the pump over the weekend to make sure it worked before taking cuttings. I have never had a problem with products from HTGSupply.com before but you don’t want to take your cuttings and find out the pump does not work.

The plugs are a very nice component of the 8 cuts bucket. They have preformed slits that hold the cuttings in place and make it easy to put the cuttings in. You can also order them separately if you loose or rip them. They also come in different colors which is a great thing if you are taking cuttings from different varieties of the same species of plant… the colors will be a marker so you know which cutting is from which mother plant

I have written about cuttings before. Make sure when you take the cutting you put the stem in water (or the clone bucket) as soon as possible. I took the bucket into my greenhouse where I had some tomato plants growing under a 600 W HPS with secondary lighting of diffuse sunlight. As soon as I took all 8 cuttings I put them in my grow tent and put them under the UFO LED and plugged in the pump.

Make sure when you put the plants in the plugs a few cm (1-4 inches) of stem are getting wet below the plug. I would suggest that you cut the leaves off a node and have the node under the plug (getting wet) as well. Many plants will produce roots at the node. I used only tap water in the bucket for the first two days, and then decided to use Hormex to improve my odds of clone success. I added a few ml of Hormex to the water reservoir on the second day. I was not going to use a rooting hormone as tomatoes are pretty easy to take cuttings from, but I saw it on the shelf and figured I might as well use it.

On day four I saw roots beginning to form on some plants. There was some brown ‘funk’ that developed on some stems, but after I added the Hormex, and some fertilizer I only saw health white roots in the next couple days.

When you first take your cuttings, you may notice they are a bit droopy or wilty. This is ok for one or a few days. It might help your success to mist the plants, but make sure they have a chance to dry off before you mist them again or you may have fungal growth. Also, you do not want to have too much airflow. I like the grow tent because it is easy to control the small environment. Some wilting is o.k. but he leaves of your cuttings should have some turgor pressure (they should not be totally limp, and look dead). Once roots start to form the plants will be able to take water in and the leaves should start to perk up a bit. As I said, I had healthy established tomato roots the end of one week.

Good Growing,
Dr. E.R. Myers

The 8 SITE CLONE BUCKET Test

2011-01-25T16:20:00.005-06:00

HTGSupply.com asked me to test out one of their 8 site clone buckets. I liked it so much I am devoting the beginning of February to it to show anyone interested how I used it to help prevent any problems. It comes alone for under 50 dollars or you can get a kit with a light. As I write this I have healthy cuttings with great root growth. (It works great!) I have added some fish emulsions to promote vegetative growth until I put the plants into a hydroponic system with gravel as a medium. As you will see in pictures, this bucket rocks!

Light Meter Uses, LED etc.

2011-01-16T04:22:00.000-06:00

I have included some pictures of a light meter I got from HTGSupply.com This is not an essential tool for good growing but there are some light meter uses that the more advanced grow could use to improve their growing.
The first thing you could do with a light meter is to check for hot spots or low light areas under you lights to maximize the space you grow in

I have written about how long HID bulbs last and a second use of a light meter for good growing is to test how the output of your HID bulbs are declining and make sure you maximize the life of the bulb. Maybe your bulbs are lasting longer then average and you don’t need to replace them, or maybe you have a below average life expectancy and your output is well below what you want.

A third use of a light meter is to get the right height for your light, you don’t want to risk your plants growing into the lights and burning if they get enough light a few inches further from your light.

Good Growing,

Dr. E. R. Myers

A Second Great LED -4 (end of semester)

2011-01-09T16:21:00.004-06:00

The end of the semester means I must end my experiment, but I hope to take stem cuttings of the tomato plants and try out a new clone bucket from HTGSupply.com with this LED and Grow tent.

This UFO LED is a great light. Plants have good vegetative growth and the flowering response is great with this light, in fact the only thing I can say is better with the T-5 is that the tomato plants were much shorter and sturdy stemmed under the T-5 than the LED. The plants in the grow tent picture above were growing much like tomato plants outdoors under the sun; they had grown tall and needed to be staked or in tomato cages. This normal growth occured with only 90 watts of electricity. The Coleus and basil and rosemary in the tent also showed the same 'normal' growth I would expect outside in sunlight. All tomato plants under the UFO have many small tomato's and many more flowers forming as well as the good upward vegetative growth.

Please compare the grow tent picture above with the post of the first day of this test one month ago to see what this LED can do

My conclusion: I still think an HPS is the single best light to use if you only use one light and a fluorescent light is still my best choice for vegetative growth of say seedlings or cuttings or small plants but even a high output fluorescent can not compete with the 2 watt bulb Tri-Band LED from HTGSupply.com when it comes to flowering. If you are growing spinach or basil or some other leafy plant you may want to stick with the T-5 vs. an LED but if you are interested in flowering or even flowering and vegetative growth you should seriously consider a LED with Tri-Band technology! My next test I hope to compare a Tri-Band LED to HID's... stay tuned.

Good Growing,

Dr. E.R. Myers

A second Great LED - 3

2011-01-04T16:21:00.001-06:00

During the second and third week I started to see a difference between the UFO LED in the grow tent and the T-5 Fluorescent. The LED had a much better flower response than the T-5. This is not surprising if you look at the light output, the T-5 is a good light because it has a broad light output (All the colors of the rainbow which makes it look 'white' to your eyes) and it has a lot of blue light. Both blue and red light are required by plants in all growth stages, but an excess of blue light will promote short bushy vegetative growth and may actually inhibit the flower response in some plant species. This UFO LED has plenty of blue and red light (In the proper wavelength for plants to use as an energy source for photosynthesis, not just so it looks red or blue to the human eye). You can see this light does promote good flowering/fruit production. What may be surprising is that the UFO uses only about 90 watts while the T-5 is using almost 200 watts. The Tri-band technology developed by HTGSupply.com really does promote excellent plant growth and lives up to much of what I have heard about LED’s. I still know there are a lot of poor quality LED’s out there so don’t assume any LED is as good as what I have shown here.

Good Growing,

Dr. E.R. Myers

The Right Height for Your Light

2011-01-02T16:22:00.013-06:00

One thing you want to do is make sure the light you use is at the right height. The light source is the single most important factor in good growing. For fluorescent lights with big bulbs (T-8 or T-12) you want the plants as close as possible, within a cm (1/2 inch). These are good lights to start seedlings under or to start growing indoors with but you can't really grow plants over one foot tall with these lights. When you move up to a high output fluorescent T-5 you can have the plants a bit further (several inches) from the light. With LED or HID you can have the light even further from your plants as the light intensity is much greater. The further from your plants the light is the larger an area you can grow in. However, the energy of light decreases over space so if you have the light too far from the plants you will get tall lanky plants that are trying to grow up to get closer to the light source. You need to find the best height for your plants and your grow environment. I blow air cleaned by a carbon filter right at the reflector and bulb of my 400W HPS and this allows me to keep the HPS light only about 1 foot above plants. With HID's the limiting factor as to how close to have the light to the plants is usually heat, these bulbs emit a lot of heat and you must keep them 1-2 feet above your plants or the heat will harm your plants. You can look for brown leaf tips as a sign of high heat stress. I sometimes put a 600W HPS several feet above a lot of plants that get some secondary light through a window. This light and the hour of sunlight on sunny days is all I need to have happy healthy plants in my solarium. LED's do get hot too, but not as much as an HID. WIth LED you can have them two feet or more above the plants, but the closer the light is to your plants the more intense the light. More intense light will speed up the growth rate, and the flowering rate, so long as the lights don't burn your plants

If your plants do grow too close to the light you will have tissue damage, with low energy fluorescent you will get yellowing with T-5 and HID you will get brown leaves and branches (DEAD) on the parts of the plant that are close to the light.

A Second Great LED -2

2010-12-28T04:23:00.003-06:00

I used a grow tent again for my second test of a LED from HTGSupply.com and it turned out even better than I would have hoped. The new 2 watt bulbs really increase the light intensity and everything that I said in my first LED test about the 120 watt Tri-band is true for the 90 watt UFO (X2). The UFO also incorporates the Tri-band technology but with two watt bulbs it is an even better light with LESS electricity usage. The next few posts will document with words and pictures my experiences
I have recommend to many people to start plants under a fluorescent light as it promotes short node length and good vegetative growth with its high blue light output. With the big bulbs (T-8 and T-12) I recommend cool white for its high Kelvin rating and the blue bulbs for the T-5 HO. I have propagated cuttings under an LED and started seeds with my first LED test, but there is no reason not to use fluorescents if you have them, as I do.

I was happy to see that at the end of one week both lights had induced flowering in the cherry tomato plants. The basil and Coleus were smaller and younger and did not begin to flower in the first week. Remember that the LED is using 90 watts and the 4 bulb T-5 is using around 204 watts.
Good Growing,
Dr. E.R. Myers

Merry Christmas (cactus)

2010-12-24T23:59:00.004-06:00

This is a Christmas cactus that my grandfather gave me as a cutting. (There may be some genetic basis for my joy of growing). There are several species all in the genus (Schlumbergera) and native to the South American tropics. The green, flattened, leaf-like structures that make up the majority of a Christmas cactus are actually modified stem segments called cladodes. In most cacti, the leaves have been modified into spines which have many different functions for the plant, or as in the Christmas cactus, the leaves / spines are absent.

The plants flower around the winter solstice (Christmas time) because like with many plants the longer period of darkness, not the length of light, signals the flowering times. In fact many of our favorite holiday flowers are "short-day" plants meaning they require at least 12 hours of uninterrupted darkness to stimulate flowering

You should never over water a plant but Christmas cactus like to be moist, so water as soon as the top of the soil is dry. To add more humidity around a plant that is growing in a dry winter home atmosphere, place the pot on a tray of pebbles and keep the pebbles moist. Christmas cacti grow well in a bright location out of direct sunlight. Apply a general fertilizer (like 10-10-10) every month. You could use a higher flowering fertilizer (high in phosphorus) starting in September to maximize flowering.

Good Growing,
Dr. E.R. Myers

Cuttings with LED Lighting

2010-12-21T04:22:00.017-06:00

I decided to try taking cuttings of rosemary and try out Juicy Roots and see if there is a difference when the cuttings are put under fluorescents vs. LED. I took 6 cuttings and put half under a big tube fluorescent light and the others in the grow tent with the UFO. You can see with your own eyes the results (below). Now with such a small sample size this is certainly not scientific, but my goal was to test a LED with cuttings and I can now recommend LED’s from HTGSupply.com for growing plants and starting cuttings and as you will see in the next few posts, flowering/fruit production. I would have advised anyone to put the cuttings under a dome but I did not. Learn from my absent minded mistakes, you will greatly increase your cutting success if you keep the humidity high for your cuttings until roots develop.

Good Growing,
Dr. E.R. Myers

A Second GREAT LED- UFO - 1

2010-12-17T16:24:00.015-06:00

The next posts follow my second use of an LED as a stand alone light for plant growth

As I said in my first test of a LED I have gotten many E-mail's asking what I think about LED's for plant growth. The use of LED’s in indoor growing is on the rise. As before I will be growing plants (Tomato, basil and rosemary this time) in a grow tent but this time I am using a UFO LED From HTGSupply.com. I am happy to report that this LED is even BETTER than I expected, I am using a 2 watt bulb version. Of course I will show you the pictures to prove it. I can not say you will get the same results with all LED lights no matter the wattage. I know HTGSupply.com has done a lot of research and this is a proven LED that they developed specifically with photosynthesis in mind. Many of you know that unfortunately the easiest (cheapest) to produce LED that emit blue and red colors (to human eyes) are not in the optimal wavelength (color) that most plants need to drive photosynthesis.

REMEMBER: Not all LED's are the same!

Cost is a factor in all purchases and as you may know LED lights are an energy efficient light source. This means you will pay less on your electricity bill each month, forever. Energy efficiency also means there is less heat as a by product. With less heat, growing in small spaces is easier and you need less electricity and equipment to remove heat. And, LED's last for years. You should replace an MH bulb yearly and a HPS bulb every 2-3 years (LINK how long bulbs last) or you will have a large loss in light output and yield. An LED will not loose light intensity for thousands more hours than an HPS so it lasts you years longer. Keep that in mind if you are going to grow for a long time.

THE UFO LED from HTGSupply.com

Good Growing,
Dr. E.R. Myers

Sugar Additives and Growth After Germination

2010-12-14T16:23:00.002-06:00

If molasses benefits plants due to its sugar content, then maybe other sugars or carbohydrates added to the soil would also increase growth. I encouraged some of my students to test this hypothesis by suggesting they test the effect of adding sugars to sunflower seeds in potting soil. (Sadly, I did not have molasses the day we set up the experiments) We watered plants right after the seeds were planted. Each group watered half their plants with the additive (sugars or Fox Farm Big Bloom were tested this semester) and the other half of the plants only got tap water. We then reapplied the additive each week for three weeks until we measured plant growth. (Additives were 5ml per 1/2 L of: Coke, 5 hour energy drink, tea that had dextrose sugar and straight table sugar (sucrose). All plants were watered with tap water as needed throughout the rest of the experiment. We saw no increased growth (measured via height and biomass) in any sugar groups after three weeks. The Fox Farm group was significantly bigger in height and biomass. An interesting observation was most of the sugar additive groups had mold (no other pots had mold accept one’s that had added sugar). This mold may be related to the most important piece of data, that there was a significant reduction in percent seed germination found in groups that used sugar additives compared with those that added high phosphorus fertilizers or just tap water. I would not recommend using sugars until your plants are larger and more established and interacting with soil organisms that are beneficial. I hypothesize that by adding sugar before the seeds germinate you are making it easier for harmful microbes that are wide spread in the environment and better adapted to take advantage of a sugary environment to dominate the soil. By adding sugar once the plant is larger and has established a relationship with beneficial microbes (already in place) the beneficials will thrive with the new food source and so will your plant. Next semester I will be sure to bring in molasses… until then, stay tuned and…

Good Growing,
Dr. E.R. Myers

More on Molasses - Molasses II

2010-12-05T16:22:00.002-06:00

In my last post about molasses (Be sure to read the comments too) I recommended you can add molasses a table spoon per gallon at any stage of the growth cycle so long as you don't get harmful bacterial or fungus. There are a few products that contain sugar or molasses (see p.s. below) but if you want to buy straight up molasses’ look at the label before you use it and compare the nutritional information and nutrition facts – Here is the information on some molasses I have: Serving Size: 1Tbsp. (21g). Servings per Container: About 24. You can make 24 gallons with this one jar. Sodium - 65mg. The lower the sodium the better this is not good for plants so compare before you buy! All of the following are beneficial to plants and more is better when comparing brands of molasses -- Potassium - 800 mg. Total Carbohydrates - 13g, Sugars - 12g, Protein - 1g, Calcium - 2%; Iron 10%; Magnesium 15%; This brand does not have sulfur, but I recommend you do use molasses with sulfur (see comments about sulfur in previous post) A good grower will see this in not a bad fertilizer, which is not surprising being made of plants it has the molecular pieces that plant cells need for their metabolic reactions. Molasses like compost supplies mineral nutrients essential for beneficial microorganisms to survive and thrive and molasses has lots more sugars which are an energy source for beneficials. A secret to successful organic gardening is feeding plant materials to microorganism populations in the soil/medium. There is a real benefit to soil microorganisms from organic amendments like molasses, kelp, or other plant based products since they are quickly and easily available as food to soil microorganism and/or plants. If molasses does improve growth or flowering and many say it does, then it may prove the old adage true - “Feed the soil not the plant.”

By the way, if you do see improvement with molasses you may want to grow with increased organic matter, it would be best to mix things, like coir and/or compost with soil, to create a heterogeneous environment with lots of food for the microbes. Also, pH is a crucial factor, Coir has a lower pH than soil so mixing it could improve or harm growth depending on what plant and environment you grow in. If you are going to try to grow or improve growth with organic gardening, a pH meter is a good investment.

I will have future posts about beneficial bacteria, please E-mail any comments or questions about this or other topics to me at askthedoctor@htgsupply.com anytime.

Good Growing,
Dr. E.R. Myers

P.S. Perry at HTGSupply.com reminded me that some of their products contain sugars like, Sweet Leaf, Sugar Daddy and Carbo Load. In fact, Sweet Leaf and Sugar Daddy have molasses in them.

E-mail -- How to use Molasses

2010-11-28T04:24:00.004-06:00

Dr. Myers,

When is the right time to use Molasses in the growing cycle? How much should be used? I am using the Fox Farm nutrient package in soil-less mix. Do you add the Molasses to the regular nutrient feeding or add it to plain H2O that is
used in between feedings?
Hello and thanks for your question. I have not personally used molasses but there is a bit of information out there concerning molasses and/or sugar additives. Molasses is produced during the refining of white sugar from sorghum or from the juice of sugar cane. There is unsulfured molasses, but sulfur is a trace element so for plants I’d not use unsulfured molasses (Sulfur is not the most important thing so if you can only get unsulfured no biggie). Molasses is available in at least three colors/flavors light, dark and blackstrap. The degrees of color are a result of carmelation and how concentrated the molasses is. Light molasses is from the first boil of the cane, dark is a product of the second boil and blackstrap is a product of the third boil and before being sold as a plant supplement was mostly a waste product. This is the same story with coco coir it used to be a cost for a company to dispose of but now it is sold as a product. Maybe it is not so bad being green. If you find success in using molasses what a win-win; a former waste product that is sold to promote plant growth. If you are interested, I know blackstrap molasses does have another use, in brewing stouts and other dark beers.
Molasses if you break it down is a plant derived substance that contains potash, sulfur, and many trace minerals which can be limiting factors, it has a lot of carbohydrates (small carbohydrates are called sugars) which are an energy source for plants and/or soil microorganisms and in some studies the sugars act as a chelating agent, which means it will help plants to absorb nutrients that otherwise they could not.

There are studies that show the benefit of molasses is it provides sugar to the plant and/or soil microbes which will promote growth either way if nutrients are a limiting factor. I want to stress as I have in the past that if you want to improve growth the first and most importing thing is increasing the amount of light ALL your plants get, not just a few directly under the light. If the molasses provided a limiting nutrient you can apply it in any and all stages of plant growth at a tablespoon per gallon. But, read the limits of molasses below before you run to the store and buy up all the molasses.

Limits of molasses: I understand that many people think that adding molasses the last few weeks of flowering/fruit production will increase flowering, or that it might improve taste. Since the sugar will be metabolized (completely broken down) in the mitochondria of plant cells into CO2 and H2O and energy, it must be some trace mineral in molasses itself that alters flavor. I found no scientific study that showed improved taste due to added sugar. I did read one scientific study that said adding various sugars had no affect on fruit flavor good or bad.

While there certainly are benefits to using molasses, if you add the molasses (sugar) you do need to watch for unwanted species of mold or other pests growing in your soil . You are creating an all you can eat buffet, and you may get undesirable microorganisms in your medium.

I have also heard people suggest you foliar feed plants to get the benefits “right in there” the truth is the stomata or pores in leaves are designed to convey gaseous CO2 and H2O molecules and I don’t know how the sugar would move around inside the plant if it entered via the leaves. Also, since the stomata are on the under side of plants most water nutrients will wash off the plants if not sprayed on the underside. On the other hand, the roots are an organ designed to take in nutrients that are dissolved or soluble in water. Whether molasses can get into the leave or not can be debated but you can not argue that if you foliar spray molasses you are creating an environment that many harmful organisms can thrive in I would never recommend spraying sugars of any kind on leaves or flowers in any stage of growth.

I think there is a lot of truth in the school of thought that the sugars/carbohydrates in molasses actually feed the microbes in the soil, or hydroponic tank, and that this increase in microbe metabolism and its supply of available nutrients to the plant is what improves growth. Either way, it seems you can add molasses a table spoon per gallon at any stage of the growth cycle so long as you don't get harmful bacterial or fungus. I would be interested to hear if it makes a difference from any of the people that read this blog, maybe you could try using molasses on some plants and not others. The problem I read in many personal experiences with molasses on the web is that they used molasses on all plants and they were 'great', so therefore molasses is great? Nope, you don’t know if it was the molasses, genetics or the light from HTGSupply.com you are using that gave you the environment to be a good grower. A test with a control group is needed to prove it, you should use molasses in ½ the plants (that are all from the same mother plant or F1 generation hybrids at least) and compare them to the ½ you used molasses with.
That should answer the E-mail but in my next post I will continue discussing molasses in more detail, stay tuned!!

Good Growing
Dr. E.R. Myers

A Proven Fertilizer for Success - 1

2010-11-22T04:25:00.020-06:00

Many of the E-mail’s I get are people asking me what fertilizer I use, or what the ‘best’ fertilizer to use is. The truth is it depends on the environment you create to grow in (Consider the medium plants are in, average temperature, high and low pH, source of water etc.) and most important what species of plant you grow. I can say that one thing that seems to be true in all cases is that organic based nutrients are beneficial and seldom harmful when used as directed. Keep in mind I have repeated a previous experiments (bottom of post) showing that adding more than the directed amount of nutrients actually SLOWS growth.

If you are starting out or want to try something different that you know will work… I like the Fox Farm products and recently I have been using a fertilizer that contains many beneficial organisms. Peace of Mind from Fox Farm

I use this indoors mixing about 1/4 cup of Peace of Mind with my soil/perlite mixture when I potted up into 1 gallon containers. This semester my plants grew better than they have in a few semesters. This excellent growth continued even without adding more Peace of Mind as I potted up into 5 gallon buckets of soil mixture. I figured any microorganisms in the 1 gallon would grow and increase in number in the warm, moist soil waiting for them in the 5 gallon bucket. There was indeed continued good growth as the plants continued to grow for a week in vegetative and then begin to flower using my standard fertilizers. The plants had healthy looking dark green leaves through out the grow cycle (Seed to flower) where as in the past two grow cycles I had been dealing with some yellowing and necrosis as the plants began to flower. I lost one plant last semester and a few others I was worried would not make it. This semester I had none of that, which may mean I had a nutrient deficiency, or the plants had a weaken immune response and the beneficial organisms and/or nutrients helped boost the plants immune system.
I also used Peace of Mind from Fox Farm outdoors for my landscape plants. I had a great year in both growth and flowering for all the plants that I used the Peace of Mind from Fox Farm- with. The greatest example may be that the Bradford pear tree in my back yard is having a monumental year first with flowering and now in the fall fruit production. In fact it is sort of a pain, never in the 7 years I have lived here has the tree been dripping with pears as it is now. They cover the ground with the leaves and stick to your shoes so you have to watch for them. I sweep and rake them daily or face the consequences of the damn fruits squished in my shoes. There are many species of birds, squirrels, raccoon and opossum eating fruits on various day and night shifts but still so many fall to the ground and are left neglected to rot. I know comparing this tree to another in the front yard and a few around the block that did not get the fertilizer is not a scientific experiment, but I think there is a real benefit to all plants to have microorganisms living in the soil with them. After all, these organisms (plants, soil fungi and soil bacteria) evolved together and therefore why would anything be better for the expert or average Joe grower? If you want to grow ‘organic’ and be a good grower you will have to be mindful of beneficial organism.

If you are looking for something to try, I am very happy with Peace of Mind from Fox Farm and I have used and will use again many products from Fox Farm all of which I get from HTGSupply.com.

Good Growing,
Dr. E.R. Myers

Day light savings, a timer and your life schedule

2010-11-11T16:23:00.003-06:00

This year I have my home garden flowering 10 pm ‘off’ 10 am ‘on’. I like this because a couple days a week I get home at 9 and I like to unwind by watering, caring or just staring at my plants. With day light savings, I went down stairs after work and the light was OFF. Ohhh man. It took me 3 days to remember to alter the light back to my schedule and I figured this was a good topic to write about.

So, what is the best way to get your plants back on your schedule? Well, you could just leave the light at 9 pm ‘off' 9 am ‘on’, but I don’t like that. So, the second choice is deciding if you are you going to shorten a day or lengthen a night. It won’t make or break your growing but I would recommend having a longer night. I say this because as you may know plants keep track of day length with a molecule called phytochrome. There are two forms of phytochrome, light and dark. Light energy makes light phytochrome, and light phytochrome changes to dark phytochrome without light. The ratio of light to dark phtochrome molecules is what triggers a plant to flower. So, if you lengthen the day by an hour, you will have more light phytochrome than dark which may confuse the plant and if you are already stressing plants with too much nutrients, or light contamination at night etc. this added little stress might be the final straw that makes your plants have problems.

What I did is changed the on time an hour, so that the light would come back on at 10 am. This gave my plants a 13 hour ‘night’, which if anything would speed up the flowering response. Then, the next day with the lights on I moved the lights off time back an hour and now I am back to my original time of on and off.

Good Growing,
Dr. E.R. Myers

E-mail - Lumens Needed per Square Foot

2010-11-07T16:20:00.013-06:00

Hey Doc, how many lumens are needed per square foot?

As with all my answers it depends on the type of plant species you are growing but from my experience and everyone I talk to at HTGSupply.com says when considering the light and the size of your grow area (square feet) that you should go with 4x4 feet for 400 W HPS and 5x5 feet for 600 watt. When considering just lumens say for other types of lights, basically, the lowest I would recomend is 2500 lumens per sq. foot but I also know people that have up to 10000 lumens per sq. foot. I have also read you want at least 1000-1500 lumens per square foot. When considering light output usually more is better, what you want to look at when you buy a light is the area you use as well as the intensity of light being emitted. It might be better to spread out lumens into a larger area rather then concentrate them in a small area. Or you may want to have very high intensity in a small area, it depends on the plant you are growing. You can spread out the lumens by having the light higher above the plant and may want to experiment with hanging your light at different heights above the plants. (HTGSupply.com sells some neat light hangers that are adjustable) Keep in mind, once a plant gets its maximum amount of light, there is no way to increase photosynthesis beyond that so any more light intensity is wasted on the plant but costs you money in electricity and will generate heat.

Good Growing,
Dr. E.R. Myers

E-mail - Preventing Unwanted Seeds or Pollen Protection

2010-11-03T00:00:00.008-05:00

Dear Doctor Myers,
I'm having a horrible time with my plants going to seed. My flowering room and vegetation room are separate. I don't know when or where the pollen has come from and I really don't know what to do. I will have the flower room empty very soon and can clean the room but it's lined with Mylar. How do I clean the pollen out of the whole grow room?

Thanks for your question. There are many reasons to prevent seeds first would be to ensure a true breeding line. To do this you will need to make sure there is no pollen (plant equivalent to sperm) in the room where you are inducing flowering. The easiest way to do this is to remove the male part of the flower (plant sex link), or male flowers or male plants, depending on the species of plant you grow. If you grow plants that have a perfect flower (male and female in same flower - like peas) you will have to remove the male part from every flower. If you have both male and female flowers on the same plant you can remove the male flowers but both of these situations you will have a hard time not getting seeds if you are not consistently and accurately checking your plants.. If you grow plants that are male and female (separate sexes) you can remove the entire male plant. A problem with plants that have separate male and female plants is that you may have a plant that is a hermaphrodite (has both flowers usually a small number of male flowers on an otherwise female plant), these hermaphrodites can be due to genetics or stress from high heat, or light getting in during the dark cycle, or poor nutrients (check for these problems in your garden as all can cause hermaphrodites)... If you think you have hermaphrodite plants, you may want to start over with different seeds to be safe.

Pollen from some plants can float in the air for days. You need to wipe down the Mylar and all surfaces in the room with a cleaner that has ammonia to kill any pollen. High temperatures and moisture can also kill pollen, so after you wipe down the room, try to have very high temperatures if you can for a couple days (leave light on with out exhaust fan for example). And spray the room with a water bottle once a day. Pollen usually is only viable for a couple days at warm temperatures.
I have written about pollination in previous posts

A carbon filter might help cut down on pollen production, but it could also blow pollen around the grow room and make your problem worse if you have the air blowing across your plants like I have recommended in order to increase airflow and the growth rate. However, If you vent the carbon filter air outside the grow room, preferably outside the building, that might cut down on pollen.
Good Growing,
Dr. E.R. Myers

How to Select the Right Plant to Breed

2010-10-30T16:21:00.003-05:00

I would like to begin with a story about how any one can get caught up and forget what is important... I follow my own advice about how to breed the best plants but one thing even I forgot is to prioritize your breeding. This is especially true if you are growing for taste and or flavor. The soil or nutrients you provide your plants are important, but genetics is just as important (maybe more so) and genetics comes from breeding. My story… I had been breeding a variety of pepper for a few generations. I followed all my own advice, picking and breeding the biggest plants but one day I realized that some peppers had that zip when I ate them, and others did not. Some of my peppers were mediocre! What had happened was that I was picking the best growing plants, not the best tasting peppers. I began to use recurrent selection, choosing only the best tasting peppers as mothers each generation. Sometimes these were not the first to flower or first to mature, but they tasted the best. I had several mother plants each breeding cycle but only kept seeds from a mother plant who I tasted and enjoyed. If you are growing things to be consumed you will have to breed several plants and then only choose from a mother that has the taste / pizzazz that you want. I was not mindful of why I was breeding, I was just breeding the best looking plants, not the best tasting.

How to select the best plant to breed: Use your powers of observation to select and REMOVE inferior plants throughout the growing process. Mediocrity is unacceptable. Make notes about each plant as it grows. Which one’s have longer internodes, which one’s branch the most, notice the shape of the leaves, notice the first to germinate or flower etc. You should have a primary goal of what you want, whether it is taste, yield or color, but if you can incorporate overall vigor into you plants all the better. Even if you just want spicy peppers, you should try to pick plants that are spicy AND grow vigorously and have good yield, and mature fast etc. Spicy is great but if you can include other good traits, that is the magic of being a good breeding. Through breeding you can make your plants better on many (all?) levels

How I breed plants: When I breed plants, I pick the first few seed that germinate, and the rest are disposed of. I then label the plants that are the most vigorous growers, the first to flower, the biggest flower, or the best taste etc. I choose only a percentage of plants at different stages of growth to continue in the growing process. Some seedlings don’t get potted up if they are inferior. They are sent to the compost pile. Some plants that grow slow are not allowed to flower. (Also to the compost pile). A term for this is that I am culling (the verb is cull) inferior plants and mediocre plants as they grow. If you have the seeds to grow extra plants it is worth it. I germinate seeds in small containers of coco coir or vermiculite or seedlings trays packed with soil. A tray holds over three dozen seeds. If the seeds are fresh I get 100% germination. Older seeds will have a lower germination percentage. From the 30+ seeds that germinate I pot up 20 seedlings under fluorescent lights knowing that I only have room for 10 of those plants max. in my flowering area, (one 400 watt HPS). I start plants under standerd house hold fluorescents and then I place the 20 plants in larger containers under a T5 HO florescent light. As they grow space gets limited, so I pick the weakest plant and I cull it. If you are growing plants with separate male and female plants you can induce flowering so you can cull the sex you don't want. When it is time to flower, as I said, I only have 10 plants maximum under my 400 HPS . So, as the plants grow I pick the best growing plants to induce flowering and/or breed but cull the rest. Sometimes I might put the mediocre plants outside (See starting seeds indoors) if I am doing this in spring, but they are never in the breeding population. Whatever you are breeding for, be observant, keep records and you will reap the rewards.

If you have questions about breeding feel free to E-mail me.

The art of plant breeding comes in knowing your crop, being curious and making observations.

Good Growing,
Dr. E.R. Myers

E-mail - Rockwool and Seedlings

2010-10-23T16:22:00.003-05:00

Hello Dr. Myers,

I’m using Rockwool so should I tease the Rockwool so that its covering the top of the seeds and just let the seeds push their way through or should i just leave the seeds uncovered inside of the propagation tray with the dome

I have written about Rockwool in general in a previous post about hydroponic mediums. Rockwool can hold large quantities of water and air which aids root growth and nutrient uptake. So, if it is sitting in water it should be able to keep the seeds wet enough to force germination if the seeds are just on top of the Rockwool. (See warning about seedlings and standing water below) The seeds could be put in the little holes in the cubes and left to come up on their own if they are the size of apple seeds or larger. Smaller seed could just be put on top of the Rockwool. As I have said, Rockwool is used principally in hydroponics. However, I used to start the seeds in a tray in Rockwool cubes and then put the cubes in soil. The Rockwool like the coir plugs I use today just made it easy and mess free to start seeds. The nice thing about Rockwool is its fibrous nature also provides a good mechanical structure to hold the plant.

Hey Doc,
If I had a seedling in a Rockwool cube that I transplanted into a flood and drain system using hydroton what level should the water come to in relation to the Rockwool? Should the water line come just below the Rockwool?

Perry a manager at HTGSupply.com gave me some info. for this post since I have not used this type of system. With Rockwool, you could either have it flood and drain, or have the cubes constantly touching/sitting in water. If you have small seedlings then you may want to flood and drain because the cubes could be too saturated when sitting in water and cause root rot.
Many seedlings are just are too small to pull air into the Rockwool (it will be very saturated in standing water) but after a couple sets of true leaves most plants will be big enough to pull air into the cubes even if the cubes are sitting in water.

Good Growing,
Dr. E.R. Myers

E-mail - LED and cuttings I

2010-10-16T16:42:00.003-05:00

Hello Doc,
What is the best LED for cuttings?

Hello,
I have only tested the Tri-band light, specifically the 120 W.
I have not had cuttings under it yet, but I have grown plants from seed to flower so I assume cuttings would work under the Tri Band too. {Dear reader: Please E-mail me or post a comment if you have a good cuttings system that uses LED, with a picture I may be able to get you something from HTGSupply.com}. As I have said in past blog posts, not all LED’s are the same, some do not work very well for growing plants, I know the Tri Band does. Basically, the higher the wattage the more light output so if you have a lot of clones (in a larg area) or big mother plants go for the highest wattage LED you can afford. I think the 120 W is a good place to start if you have a small set up.
I usually recommend using fluorescent lights with cuttings, and maybe even mother plants. A T-5 light might be a good choice, it may use more electricity, depending on how many bulbs you use, BUT it will have a lot of energy in the form of blue light which promotes vegetative growth. You may have to put the T-5 lights vertical beside a large mother plant, and have them horizontal for cuttings. I don't know if you have a separate area for mother plant and clones. If not you will want to use reflective material to bounce light around since it might be hard to have lights at the right distance from both big mother plants and small cuttings.
I know a guy that used pieces of wood he made into a square frame to make platforms to keep all the plants at the same height. The smallest plants had three platforms, and as the plants grew, he’d take out a platform until it was just a plant in a 5 gallon container. He sometimes had to tie plants down if they grew too big, but eventually just found hybrid seeds that always grew to the right height. He then used a light mover and had many plants growing all at the same height over a ten foot area with two 400 HPS.
If you do have big and small plants in one area an LED might be good since it has high light intensity, meaning plants can be further from the light and still get enough energy from the light to grow well. You would want to keep the cuttings a few feet away from any light as big or bigger than the 120 W Tri Band.
If you do go with T-5 make sure you get the bulbs that are blue for vegetative growth not the red one's which are more for flowering. A T-5 will have a bit more heat than one LED, but it is tried and tested.
I hope this helps, I'd like to hear what LED you use, if you do and how it worked out.
Good Growing,
Dr. E.R. Myers

What Is a Hybrid?

2010-10-08T16:23:00.005-05:00

I mentioned in a previous post about buying hybrid seeds and I want to add to that topic. Keep in mind when if buy hybrid seeds, Some hybrid plants are developed for specific growing conditions, so pick ones that are right for your indoor growing conditions

Plants are usually classified as open pollinated or hybrid. An open-pollinated plant is the natural offspring of out crossing plants. Heirlooms are open-pollinated plants that have been essentially unchanged for many years. What I mean is that today's heirloom tomato plant is nearly the same as a tomato from a century ago. In general, the seeds from an open-pollinated plant will produce a similar plant the next grow cycle/season. A hybrid is a combination of two different varieties of the same species. Plant breeders usually develop hybrids for specific reasons, meaning they choose specific traits from the parents and try to combine them in the hybrid offspring. Some examples would be breeding/combining plants to produce more colorful or bigger blossoms, or fruit and vegetable plants tha are more uniform in size or more disease tolerant. Since the plants are genetic combinations from two different plants, their offspring (the F2) tend to have a lot of diversity and are not always the same as the hybrid parents.

Brief Hybrid History
From what I can tell, corn was the earliest hybrid developed for commercial use in America. The use of hybrids has extended to vegetables and flowers; and more recently, rice and some other crops. Scientists conducted experiments for many years on hybridization and saw that it often resulted in superior plants. In the 1930’s less than 1 percent of corn seed was hybrid compared to nearly 100 percent today. There must be a a benefit to growing hybrids if they are increasing in such over whelming numbers.

What Are Hybrid Seeds?
Hybrid seeds are produced by creating inbred lines with specific reliable traits and then two established inbred lines are crossed to produce first generations (F1) hybrid seeds. The hybrid seeds are prized because they produce uniform plants and also have what is termed heterosis (hybrid vigor). Heterosis can result in a large increase in yield compared to the inbred lines or lines that are out-crossing (heirlooms). What exactly causes heterosis is still unclear. Thus, hybrid seeds are produced by companies through careful pollination of two specific varieties. Normally, this highly selective plant breeding is done to bring together two traits in each of the chosen varieties so that the resulting seed has both of the traits. For example, one tomato plant may be very drought tolerant and another tomato plant produces large yields, the two plants might be cross pollinated to produce a drought tolerant tomato plant that produces a lot of tomatoes.

The down side to hybrids, as I mentioned is that if you breed/cross plants grown from hybrid seeds they typically do not produce seeds that are all the same, and often can even produce seeds that are inferior to out crossing heirloom varieties.

Though the term “hybrid seeds” is often used in relation to vegetables, any kind of plant that produces seeds can be bred into a hybrid variety.

Good Growing,
Dr. E.R. Myers

E-mail – High Humidity Cures

2010-10-02T16:22:00.004-05:00

Doc, Thanks for the quick response. I'm also having a problem with humidity. Any suggestions on how to bring it down. I have a fan to circulate the air and an exhaust fan taking air out but my humidity is still to high. Thanks for your help.
No problem I am always glad to help. High humidity usually is not a problem for plant growth but can lead to mold. I say this since high humidity won't slow down plant growth unless it is very high, say over 80% humidity. Plants need to give off water as part of photosynthesis, so if the humidity is too high it might lead to slowed photosynthesis which can slow growth and lower yields. If you don't have mold, and never did it might not be a big problem for you. I also mentioned that many pests (aphids, soil gnats, root aphids and others) like high humidity so lowering the humidity might help people that have pest problems. High humidity is also something that really limits the life of carbon filters
The easiest thing if you can spare the space and electricity is a dehumidifier. I find that when I start using my HPS, it lowers the humidity in my grow area. Many growers only have small spaces to grow in so maybe you don’t have room for a dehumidifier.
Do you have open water, as in a hydroponics set up or water in trays after you water the plants? If so you could try to cover the hydroponics medium to prevent some evaporation (not easy with some set ups) or drain the water trays a few minutes after you water so there is not standing water. If you don't have water in the room, the next thing to think about is that the plants put out water into the room as part of photosynthesis, so the more plants you have and the more you water them, the higher the humidity. So, you could try to water the plants a bit less, but not so much they wilt, which will stress out the plants and slow growth. Moreover, you could try running the exhaust fan longer, maybe even when the lights are out, or upgrade to a bigger fan which will move more air/water vapor out of the room. You should try to exhaust the air to the outside of the house, otherwise you are just moving the humidity around your house and not really getting rid of it. Something else to try is to put corn starch, baking soda, talcum powder or silica gel in the room, these tend to absorb moisture. You will need to replace them every month or less if you have very high humidity. I hope this helps.
Good Growing
Dr. E.R. Myers

Buying and Saving Seeds

2010-09-28T16:23:00.009-05:00

Seed packets for sale at garden centers or other retail stores are often hybrid seeds (See later post about hybrid plants). Hybrid plants often grow bigger and yield more than nonhybrids. Hybrid seeds are usually more expensive due to the time and cost of breeding etc. If you don't mind buying new seeds each grow cycle then hybrids are a good choice. Look on the seed packet to see if the label says "hybrid." The packet will also give climate recommendations for that species. (See the USDA hardiness zones under Useful Links on this blog) Some hybrid plants are developed for specific growing conditions, so pick ones that are right for your indoor growing conditions. If you use HID’s you may want to use varieties that are heat resistant for example. Growing indoors means that you can grow even tropical plants in any area or any time of year. You can grow any plant on Earth if you try. Other examples of indoor considerations are to grow dwarf varieties for growing in small spaces or early maturing varieties to help you speed up the growth cycle which is something that might appeal to you if you are in college and are on a semester schedule.
Saving Seeds
Some good growers like to gather seeds from their plants and save them to plant the next grow cycle. (See my post on how to store seeds) While I have suggested it may be better to buy seeds (link to buy seeds) collecting and growing seeds may be an interesting way to experiment and save money. You should know most hybrid seeds, due to genetics, will produce inferior offspring or plants with different qualities and only a few will be the same as the original parents. With a small garden you will need some luck to get improved plants. If you want to be self sufficient you should buy heirloom seeds rather than breeding and planting seeds from a hybrid plant. If you don't want any hassle and just want to grow good plants all the time, it's best to just buy new seeds. However, if you are curious and have a large garden or want to try crossing two hybrids together to look for new combinations of traits you can always try. If you cross two excellent varieties you should get above average plants at least. It might be good to have a second area for growing that you devote to breeding if you want to advance to the next step... that is another topic for the future.

Good Growing,
Dr. E.R. Myers

E-mail- Screened Enclosed Plants and Polination

2010-09-23T04:22:00.002-05:00

Hi Dr. Myers
You have answered questions from me in the past and I do have another one.
In addition to my indoor garden, I have an outdoor vegetable garden. I just recently moved these plants inside my screen-enclosed pool area. Question: doesn't tomato, pepper,etc. rely on bees and other insects to pollinate and create the fruit ? So, if these vegetables are enclosed..... they will not ever produce fruit because insects and bees cannot get to them..... is this correct ? Thanks in advance
Thanks for your E-mail. I am always happy to help, if I can. You have a good question, the answer is it depends if the plants are self pollinators or cross pollinators. Self pollinators are plants that produce flowers that are usually fertilized by their own pollen, commonly when the male and female flower parts are contained within the same flower. These plants usually don't need an insect polinator. Cross pollinators are plants with flowers that require pollen from another flower -or from another plant to produce a fertilized seed and the fruit that surrounds it. Cross pollinators commonly require the help of insects or the wind or YOU to achieve pollination.

Self-pollinated vegetables include: bush and pole beans, lima beans, chicory, endive, lettuce, most peas, and tomatoes. These plants don't need any help they will produce fruit if they get enought light and nutrients.

Wind-pollinated vegetables include: beets, chard, sweet corn, and spinach.

Insect-pollinated vegetables that won't produce fruit well in an enclosed area with out your help or insects are: cucumbers, eggplant, gourds, muskmelons, mustard, okra, parsnip, hot pepper, pumpkin, rutabaga, squashes, turnips, and watermelon.

You may want to see my post about how to collect pollen and do so for some of your pepper plants, all the flowers should produce it, and use your finger or a brush etc. and put the pollen from one flower (or better yet from one plant) into another. Also, look at my Blog postings about how to transfer pollen.
Good Growing,
Dr. E.R.Myers

Terminator Genes - Keep You From Breeding Your Plants

2010-09-20T16:25:00.001-05:00

I have talked about breeding plants, but did you know that it is now possible for corporations with biotechnology to insert genes into plants that will enable them to kill any seeds you get from breeding. By inserting three genes into a plant Monsanto, and any other large corporation can effectively force you to buy seeds from them forever. The art of breeding and crossing new varieties, something that human cultures have done for… well since we started cultivating plants 10,000 years before present (YBP) would be gone forever into the world of corporate profits.

How does this terminator technology work? Well, one example would be to insert three genes into a plant so that it can be sterilized at any time in the breeding program. First insert a gene into the plant that produces a toxin that kills the seedling as it begins to germinate. To keep this gene off (so it does not make the toxin), a section of DNA called a security wall is placed between the toxic gene and the gene that regulates it being on and off (sorry this is complicated stuff stick with me here). A second gene called a scissor gene is also inserted into the plant; this makes an enzyme (called recombinase) that cuts out the security wall turning the toxin gene on. A third gene makes a protein that represses the scissor gene (keeps it from making recombinase). Now as long as this third gene is active, the plant can reproduce normally. If however the third gene is activated by some chemical, say an antibiotic then as the seed grows it will release the scissors gene in all its cells including one's that form the seeds so that seeds from that plant will never germinate, thus ending the breeding line. By inserting this terminator gene group into breeding lines, the companies can continue to breed their plants, and they simply have to spray the seeds they sell with the antibiotic before the sell them guaranteeing that no one can grow a plant without getting new seeds from them. This is sort of like a time bomb, you insert the terminator genes and breed away until you get a variety you want to sell, and then you spray the seeds with a chemical so that once the seeds grow the terminator genes are on. You will still be able to clone a plant with the terminator genes, but as I said cloned plants keep track of time so after a few generations you often see a decrease in plant growth and vigor.

This is not going on now, that I know of, but it is not science fiction either my friends. There have been court battles about this so it is possible that the terminator genes can be marketed, and theoretically could be put into any plant species.

To me, this is just another reason to support small local growers/breeders and to breed yourself, keep the plants in the hands of humans, not controlled by corporations
Good Growing,
Dr. E.R. Myers

Are You Wasting Money on Expensive Seeds?

2010-09-13T04:28:00.011-05:00

Do you buy new seeds or clones everytime you grow? Have you ever figured out how much you spend each year on this? With a few supplies from HTGSupply.com you can clone your own plants or you could try your hand at plant breeding and pay next to nothing to continue growing...

I have been breeding some plants for many years. I have not bought seeds for peppers, dill and many flowrers in years. I do this 1) becasue I can (I have a Ph.D. in plant breeding) and 2) I am cheap and don't want to pay money to corporations for seeds which I can get myself and 3) I like it, it is my hobby. However, I was traveling this summer and decided to get some new seeds to include in a breeding program. What I have noticed is that the 'new' seeds/plants have more vigor, they are growing faster and look healthier than 'my' plants. This observation was bitter sweet, my strain from many years of breeding was not as good as the one's I paid money for... but I have some awesome new plants to grow and cross with each other and 'my' plants. I should say that in the past I have also compared my plants with other people that paid good money for seeds and I won that compitation. Buying seeds from big companies is not always going to get you the best product if you don't do your homework.
Most people (including me) can not afford to grow the thousands of plants required to establish a successful and longlived breeding program that can make lots of awesome seeds. This does not mean you should keep forking out money to the seed companies every time you grow however. If you are curious, have a little time and want to save your seed money for other things you might want to try your hand at cloning and/or breeding. I will be writting about the benefits of buying seeds, and or breeding and about some things that corporations can do to FORCE you to buy their seeds with terminator genes
I continue this buying seed debate in a later post about buying and saving seeds
I have written an introduction to breeding and about plant sex, and went into some breeding technques too, if anyone is interested. I am ALWAYS happy to expand on or answer questions about past posts. The more questions I get the better resource this blog will be, so tell a friend if you like what you see.

Good Growing,
Dr. E.R. Myers

E-mail - Cooling a Grow Room for Less Than 50 Bucks

2010-09-06T16:20:00.001-05:00

Hi Doc,
I am looking to purchase a 400 hps light set from htgsupply.com and I was wondering if it would require cooling if it is left in a 12-12 cycle. I am limited in terms of cooling as I do not want to destroy my closet and am not able to drill anything. How could one go about cooling this machine for under $50 effectively?
Thanks!

Hi, The 400 is a good all purpose light, I use them myself. The answer to your question depends on the size of your closet. I also have a 400 watt in an old closet that is 8 feet high and 4 feet by 9 feet (I only grow under ½ that space at most). I have a carbon filter to blow the air around and my temperature never gets above 90F if I leave the door shut 24/7. You could use a circulation fan for far less than 50 dollars to move the heat if you don’t want to buy a carbon filter. Temperatures in the 90’s F may seem high but the temperature is in the low 70’s or less in the dark cycle so a few hours of 90F while not ideal is ok for most plants. If your closet is smaller space you will need to get some of the heat out. The easiest way is to have the door open during the lights on cycle. The best time to do this would be near the end of the light 'on' cycle when the temperature will be highest. The problem is you may forget to shut the door when say, you are not home, and the light will go off but the door will be open. (If you have irregular light and dark cycles you will have poor or no flowering/fruit). It would be ok to leave the door open for 5-15 minutes every day after the lights turn off to let all the heat out. It is good growing to have a big difference between day and night temperatures; you don't want to trap all the heat in the closet all night.

If your temperatures are in the upper 90’s or over 100F for long periods and you can’t open the door then you may need to use an exhaust fan. I say this because I had a small closet (3x3x7 feet) I used once and even a 250 Watt HPS needed to have the door open or it would go over 100F which will slow plant growth and make the plants grow tall and fall over, and flower poorly. You will need to do some minor construction, drill a hole a few inches in diameter, depending on the fan/duct you use. Wall studs are usually 16 inches apart, if you find one, move the hole don't cut one , it may be holding up the roof. The fan and duct work will blow the heat out of the room. Since heat rises you should put the fan and duct at the top of the grow room. Last option, if construction of a duct/fan or having the door open is not possible, you may want to use LED or fluorescent lights. You know I have tested the Tri-Band and you can get HO T-5 with flowering bulbs that are high in RED light

So, the first thing you need to do is to get a thermometer that has a minimum and a maximum reading and put it in the closet. Take the reading at the top of the plants under the light. Do not take the reading at the top of the closet, this will be the hottest spot, but is not where your plants are growing. If the temperature never goes above 90F at the plant tops you’re fine and have solved the problem for less than 50 dollars. If it is over 100F, and you are not growing cacti, your plants won't grow anywhere near their full potential. With temperatures in the upper 90F range or more you will need to do something to get rid of the heat like open the door, or use an exhaust fan/vent. You can get a squirrel cage from HTGSupply.com and I would recommend getting the duct and flange from them too so you know everything matches up. This option is sadly more than 50 bucks but is guaranteed. You can vent the air outside, or I like to vent it into the next room during the chilly months to use the heat more efficiently (think cheaper gas/electric bills with a warm room). I don’t grow in the room in the summer.

I would also send an E-mail to Sales@htgsupply.com, where a sales representative knows how to use all sorts of specific equipment. I just help with how to grow plants.

Good Growing,

Dr. E.R.Myers

Outdoor pests DEER

2010-08-26T16:25:00.001-05:00

The biggest problem with deer is that they eat POUNDS of vegetation every day, and they like to try new things to eat, especially fawns. One thing I have used to keep deer away from my plants and I know others that have too is a fishing line fence. The deer don’t see the fishing line and it spooks them. This fence is cheap, easy and is great if you don’t like the look of a fence or don’t want to block any sun light on your plants. This won’t work if you have very high numbers of deer and they are near starving of course. I do know someone that used it and the deer did break the line a few times, but apparently that still spooked them, the veggies were not eaten. He just put up new line and the garden made it through the summer.
I have heard if you spread garlic powder or use milogranite deer won’t come around. However, I know that deer get spooked when there is something new in their environment, which is why it seems so many products work at first. For exapmle, I freaked out deer with a wheel barrel for two days this summer, I put it under my apple tree in the garden and they snorted at it for ½ an hour each evening before leaving. Two days later they were eating in the garden again, not next to the wheel barrow but they were in the garden.

Something else I hear works is if you have motion sensor sprinklers; this will spook the deer repeatedly and may work all growing season. Get a sprinkler with the longest spray stream and longest sensor range. Another idea is to provide other forms of food, I know deer eat yarrow flowers so I don’t pick (weed) yarrow, I leave it for them to eat instead of my other flowers. This year with lots of apples on my apple tree the deer are not eating the bee balm or other plants that don’t have a fence, but they still are nipping the yarrow flowers

Deer like most people are creatures of habit, so if you start to deter them early you will have better luck, but once they get a taste for your garden and they like it, they will be back. Dogs, or cats can scare off deer, and of course an electric fence will work great too, a couple shocks and the deer will be conditioned to stay the hell away. Just be careful.

Good growing,
Dr. E.R. Myers

Pests- Snails and Slugs

2010-08-18T04:20:00.016-05:00

I have written about some indoor pests, like aphids, root aphids, white flies, spider mites, soil/root gnats but there are others that often don’t get in your house but can be a pest outdoors. Most plants can be a meal to snails and slugs. Slugs and snails can rasp (eat) a hole in leaves or sometimes they eat everything but the veins of a leaf. In severe cases they will eat whole leaves leading you to think it was a larger animal. For a while I could not figure out what was eating my plants, it looked as if a deer had jumped the fence and eaten the plant leaving only the main stem. Problem was there were no deer tracks in the soft garden soil. Slugs generally are more active at night, so they don’t dry out and often go unseen. I had a friend once that went out to check on his garden at night with a flashlight for fun and was FREAKED out when he saw his beloved plants COVERED in dozens of slimy slugs eating away at the leaves. This was a wet year, and you too will find more slugs and snails in wet years or moist areas.

The best thing about slugs and snails is that they are easy to control. You just need to use sluggo. This is iron phosphate in pellet form which in the soil actually is a fertilizer. However, when a slug crawls over the pellets their soft bodies absorb the iron phosphate which interferes with the slugs calcium metabolism so that it stops eating and starves in a few days. You can use as directed and even if you don't have slugs/snails it won't harm your plants and will provide some nutrients, so if you see slugs in your garden, why not give it a try?

If you don't use sluggo and have a random slug or snail you can control them by hand picking them off your plants and put them in salt water or soapy water or just stomp them. If you have a lot you should order some sluggo but should pluck them off with a tweezers or even chop sticks, if you use your hands you will get all slimy. You can use salt water to kill slugs but NEVER put salt on the soil, don’t get me wrong it will kill slugs, AND YOUR PLANTS. Salts make it hard for plants to take up water and nutrients so they dehydrate even in moist soil.

I have read you can surround individual plants with a copper barrier which keeps the slugs out. I’d like to hear if anyone has ever used this. I have tried egg shells and either I did not use enough or they did not work. I scattered the shells on the ground since they are supposed to cut the slugs and snails. I think you may be better off if you make a solid ring around your plants’ stem. Bonus is that eggs shells release calcium as they breakdown which is an essential nutrient for plants.

Here is my favorite  You can also use beer as a trap for slugs, Yep they come running like frat boys to free beer. You need to get a container that is deep enough so the slugs can’t climb out, put it in the ground and put in a bit ‘o’ beer. I drink Pabst in the summer myself and slugs love it too. Slugs will come crawling for any beer for meters around and then will drown in the beer. IMPORTANT If the container is not filled deep enough (several cm or inches) they will just have a drink and leave.

Good Growing
Dr. E.R. Myers

Speed up Flowering Outdoors

2010-08-12T04:23:00.002-05:00

If you took my advice and started an outdoor garden early indoors or grow outdoors already or know someone who does, you may benefit if you read this.

I suggested in past posts ways to speed up the growth cycle vegetatively and during flowering . Here is a neat trick I learned this summer to speed up flowering outdoors that maybe you can still use this summer or remember it for next. If you are growing plants that flower the end of summer i.e. in response to long nights (12 hours dark) you can speed up the flowering by placing something over the plants to fool them into thinking it is later in the season. The person I spoke with used a 5 gallon black bucket (which can be sent to your house from HTGSupply.com). You just put the bucket over the plant a couple hours before dark and take it off in the morning. Make sure first that the plant is not going to be bent and broken (you must do this when the plant is small). If the ground is uneven, make sure that you put dirt around the base so that light does not get in. Then a few hours after sun rise you take off the bucket. This will fool the plant into thinking it had a 12 hour night and it is much later in the grow season. This will speed up or start the flowering response. ONE WARNING: Do not let the direct sun hit the black bucket when it is on the plant, you will cook (kill) your plant in an hour or less. If your plants get early morning sun put the bucket on early in the evening and take it off at night and if they get late day sun, put the bucket on at night and leave it on longer in the morning.

How this works is due to the way that plants measure day length; they use a molecule called phytochrome. There are two types of phytochrome light and dark. Light (energy) from the sun or your grow light turns dark phytochrome into light phytochrome and without light, light phytochrome turns to dark. Plants that flower end of summer flower when the dark phytochrome is in a high amount. So, when you put the bucket on the plant it will have 12 hours of dark (make dark phytochrome) which will cause the plant to being to make hormones that signal it to flower. (One ‘night’ might be enough but you can do a couple more to really speed up the process)

Do this after the summer solstice the longest day of the year (around June 21 most years) and your plants will fully develop flowers sometimes weeks ahead of schedule. This works because as the days get shorter, more dark phytochrome accumulates. Normally it would take weeks to reach the critical amount of dark phytochrome but since your plants had a 12 hour (bucket) night, they have the critical amount of dark phytochrome and with the ever shortening days the dark phytochrome will stay in a high concentration and continue to signal the plant to flower. I say this because after the solstice the days get shorter so there will be less and less day light (light phytochrome).

This won’t work for light insensitive plants, or plants that will be very tall after the summer solstice, but you could use this before your plants get big and it should still speed up the flowering rate. You could also use this trick early in the summer (before the summer solstice) to see if plants have the flowering characteristics you want. You can cause your plant to flower, and then it will revert back to mostly vegetative growth until end of summer. Using a bucket to induce flowering in May or June may stress the plants and may reduce plant size, but can make sure you don’t grow any plants that have negative flowering characteristics. Anyway, I thought some of you might be able to use this trick to speed up flowering outdoors this year or next.

Good Growing,
Dr. E.R. Myers

Quick Tips on Cuttings

2010-08-06T16:23:00.003-05:00

Cloning Your Outside Plants

2010-08-01T04:23:00.006-05:00

If you took my advice and had an outdoor garden as well as your usual indoor garden (start outdoor garden indoors link) then hopefully you are enjoying good growing outdoors and you can now try another way to enhance your growing. Now that we are in August, your outdoor plants should be in full growth mode, maybe beginning to flower/fruit. If you want you could take some cuttings of your outdoor plants and get ready for another indoor crop over the fall/winter. This has some advantages, you know the plants qualities, male or female, red or blue petals etc. Another nice thing is that plants grown outdoors are usually bigger so you can take a few cuttings without harming your outdoor yield too much. Pruning an outdoor plant may make it branch a bit more. The draw back is that when you bring plants from the outside in, you risk bringing in pests like aphinds, white flies, root aphids, spider mites and more. After you take the cuttings watch your outdoor plants to see if they develope an infestation. If they have one already don't bring cuts indoors.

Another potential problem, plants tend to form roots with less success when flowering or beginning to flower, so if you are going to try this, take a few more cuts than usual since you will lose a few. The reason it is harder to get cuttings from a flowering plant is that the hormones that promote flowering often interfere with the hormones that promote root growth. If possible I would recommend removing flowers as the cells of the flowers and the tips of the branches are where hormones are produced. Depending on the type of plant species you are growing you may want to leave some small flowers since new growth (stems etc.) will come from the flowers. Keep in mind, the further the plant is into flowering the less the success you will have getting cuttings.

For cuttings, I usually recommend taking the tops/tips of growing branches with a couple of leaf nodes. I like to remove the lowest set of leaves and put rooting hormone where the leaves were growing (node) because this node where you cut the leaves is often where roots grow from. I know people that also take the lower smaller branches for cuttings. They say they get good results with cuttings. Moreover, the branches usually would lose leaves and die or at best would produce next to nothing as far as flowers or fruit, so why not use them to make a whole new plant? It might be something you want to try indoors or out.

As I have said I really like to use the starter plugs from HTGSupply.com but I have used soil and soil-less rooting mediums as well. One thing I did when I made my grow shelf for my cuttings is that I build it so that there is a slight angle away from the wall. I did this so that when I spill water it will roll off the shelf and not seep into the wall. When I take cuttings I notice that the starter plugs at the back of the shelf (high end) dry out first. You notice they start to get a lighter shade of brown as they dry, a great visual cue telling you to attend to the plants. I like the plugs because like rockwool you can let them sit in a tray with a small amount of water and the plants still have enough air around the stem to grow roots. (Roots need air and water which is why many plants don’t sprout in standing water). I have noticed with a heat mat that when the tray has some water the dome tends to be covered with condensation. The dome gets less condensation when the tray is dry, something else to key you in that you need to attend to your cuttings. I notice as over a few day that in the morning that the dome is not coverd with water which tells me the plants are drying out over night and I should give them a bit more water than the day before. You should wipe off the done each day, you want to crease a humid environment since the plants can’t take up water without roots, but you don’t want to have a lot of areas for mold to grow, since it too likes a humid environment. I often mist the plants with a hand mister the first few days. If you have had problems with mold or stem rot in the past you may want to skip this. The idea is to keep the air humid so the plant cells in the leaves don’t dry out (and die) before the plant can form new roots to take up water.
There will be some more tips on cuttings on the next post, with more pictures.

Good Growing,
Dr. E.R. Myers

E-mail - Burnt Seedlings and Proper HPS Height

2010-07-25T16:28:00.001-05:00

I just purchased a grow system from htgsupply.com --it was the hps 400w. I put my plants in my area to grow and they got burned by the light. I have plenty of ventilation for them. How far should I have the light from the plants. I just planted my seeds

Hello,
For seedlings a 400 HPS should be 2-3 feet above the plants. With larger plants with good ventilation you can have the light 1-2 feet above. Young plants in small containers will need to be protected from drying out quickly under the HPS. You should think about a thermometer with a minimum / maximum setting. If your plants are burned the temperature probably was above 100F. If it was not it might be too much fertilizer or a disease...

I have recommended a few times on the blog that seedlings are better started under fluorescents’. The T-5 high output HTGSupply.com sells are awesome, you can grow bushy, sturdy green plants a foot tall or more easily but I know they are not cheap. If you only have a few bucks get a double bulb 4 foot fluorescent light from the hardware store with cool white bulbs. With these cheap fluorescents’ keep the bulbs 1 inch from the tops of the plants and you may be able to grow plants 6 inches that are green, bushy, sturdy, and will be ready for the HPS.
Good Growing,
Dr. E.R. Myers

E-mail- Best 2nd Light and Stem Elongation

2010-07-18T16:22:00.003-05:00

Hello,
I got a q about HID lighting. Currently I have a 600w hps and would like to upgrade to another 600w. I am using a Digi ballast, and would like to figure out whether or not to use a HPS/HPS combo for flowering or HPS/MH. I know MH aren’t as lumen efficient as HPS bulbs are but I also have been doing a lot of reading on how plants don’t really care about the lumens as much as the PAR watts. So before I go buy another 600w combo I’d like to figure out whether or not I'd be in my best interest to have a more mixed spectrum or just a enhanced spectrum HPS like I have now. Lastly id like to say I’m going for the maximum yield.

Hello and thank you for the question.
As usual the answer is it depends… If you are seeing any problems with stem elongation, (you are tying plants down so they don’t grow as tall, or propping them up because they are tall and lanky) I think you need an MH, an hps/mh combo. You won’t have the light output as with an HPS but you will increase yields over your current set up for sure. If you add another hps you will have more stem elongation than you do now, the yellow/red combo so loved for flowering also increases stem elongation especially when plants are in a vegetative state. The more blue light output of an MH causes plants to have shorter stems and would actually decrease stem elongation compared to what you have now I’d imagine.

If you do not see stem elongation with your current set up I would add another hps. I say this because the yellow/red light of an HPS increases the flowering response more than the widespread light output of an MH. If you are looking for flower/fruit yield I would also go for the two HPS, again as long as you are not having a problem with stem elongation.

I think you have the right idea about PAR. An MH may have a slightly higher PAR, but the hps has more PAR in the light that induces flowering. Most other light colors (wavelengths) are given off in sufficient quantities by an HPS so a second HPS will not be a limiting factor. Yet another reason I’d recommend an HPS, an MH bulb can lose up to 50% of its output in a year. It will take an HPS 2-3 years before it has lost 50% of its initial output. That is also something to consider, you will be buying replacement bulbs for an MH yearly if you are looking at yield.

I hope that helps, feel free to drop me a line and let me know what decision you made and how it worked out.

Good growing
Dr. E.R. Myers

E-mail - MH bulbs - Plant Growth and Kelvin

2010-07-13T16:21:00.019-05:00

Hello,
I am ready to replace my old 1000 watt metal halide bulbs. I do not own a hps light and want to run a full spectrum bulb for vegetative growth and flowering. I am familiar with the new dual arc bulbs but they are not in my budget. I do not want stem elongation that I may get with a red spectrum hps in vegetative stages, but obviously need it for flowering. It is my understanding that a 6500k bulb would be best? Please help me in deciding which bulb is best suitable for good vegetative growth without stem elongation and suitable in the flowering stages also, If I have to sacrifice fast veg. growth and shorter plants for better flowers by using a 3000k lamp I will. Any and all help is appreciated.
Thank you!

Hello,
I sent your E-mail to Sales@HTGSupply.com for a specific recommendation since I am not as familiar with specific bulbs / equipment.
I can answer your questions regarding light and plant growth however. You are correct in that a lower Kelvin rating means there is more red and yellow which will promote flowering but also means stem elongation. I have always used an HPS, but sometimes I use a MH conversion bulb during vegetative. If you ever get a new light, I usually recommend an HPS but since you don't have one....

6500K MH is the BEST spectrum for vegetative growth. It is a "blue" or "cool" spectrum bulb and it really grows compact, green plants. A lot of growers use this bulb for all stages of growth. The 3000K bulb is an MH bulb and the light output is not so great if you compare it to the same wattage HPS which typically has about a 2200K spectrum which is not too far off 3000K (one reason I use HPS). However with an MH, if flowering is your main goal, go with the lower K (maybe just during flowering stage if you can get two bulbs?). You may have some stem elongation which you can correct by bending the plant tops which will make the plants more bushy, or you can have a fan blowing directly on the plants (gently) which will cause the plants to have shorter thicker stems. I do not think you will have as much of a problem with stem elongation with a MH of any type as you would with a HPS. I hope this helps, I'd like to hear from you later about how things worked out.

Good growing
Dr. E.R. Myers

p.s. These are generalities but basically an overcast Sky is 6500K. An incandescent light bulb is 2700K and is yellowish-white. The warm-white fluorescents are about 2700 K and are popular for flowering. Neutral-white fluorescents have 3000 K or 3500 K. Cool-white fluorescents are my bulb of choice for growing young plants and are 4100 K

E-mail - How Much CO2 to Add - Plant Processing of CO2

2010-07-09T04:25:00.004-05:00

Hi I read your article on co2 enrichment. Very informative! I do have one question though. How fast do plants process the co2? What I mean is, how long do I need to leave the fans off after I add co2 to the grow room? I have a small area, 6x6. My budget is low, so I am using a poor man's approach and just empting 12 gram co2 cartridges over the plants. Since the amount is so small, will the plants process it in 15-30 minutes? Also, if I am able to say purchase one of the co2 enrichment packages from HTG, how long would I need to leave the fans off? Thank you for your time.

Hello,
Glad to hear people are still checking out some of my old articles. To start with, I should say that the CO2 in the atmosphere has a concentration from 0.03 to 0.04 %. However, it is found that increases to CO2 to 0.1% of carbon dioxide in the atmosphere increases the rate of photosynthesis significantly. This was tested indoors with enclosed chambers where plants are grown under controlled conditions. Crops like tomatoes, lettuce etc. were successfully grown in the chambers and were found to be bigger and better-yielding than their counterparts growing in natural carbon dixoide conditions. I have read your rate of photosynthesis increases if you increase carbon dixoide to 0.2%.( that is 2000 ppm) After that I have not seen any studies showing improved growth.

As it said in my article you can figure out the ppm in your room with a bit of basic math and I would try to get your ppm up to 0.2% or 2000 ppm if you can. Since the use of CO2 is dependent on many variables here are some things to keep in mind: Plants will use more CO2 the higher their rate of photosynthesis. If you use a HID, your plants will use more CO2 than with a fluorescent light fixture. Also, the bigger your plants are, the more CO2 they can use. So, the more light you give the plants and the bigger they are the faster they will use up the CO2. For best results you need to add the CO2 above the plants in a sealed room with no ventilation (fans are ok just no exhaust fans) and let the plants be exposed to the high CO2 concentration for an extended time. They need to soak in the CO2 through tiny holes (called stomata) in their leaves.

How are you adding the CO2? “manually”, I am not exactly sure what the C02 cartridges are? If you are doing this with the door open, you may not get improved results as the CO2 will diffuse out the open door.

As I mentioned, the ideal system is to have the CO2 released when you are not in the room, and the door is closed. You should try to seal the room to make it air tight. This way, the plants will use as much of the CO2 as possible before it leaves the room. Also, if the room is sealed well you should leave a light fan on, this will help mix the CO2 which will have a tendency to sink to the bottom of the room. If you have an exhaust fan, you could shut the fan off during the night cycle, when there is less heat and a need for exhaust, and add the CO2 then. This will give your plants 6-12 hours of exposure (depending on what light cycle you are using) and that way you can be sure your plants are using all the CO2 they can. I understand you are on a budget, but a CO2 system with a timer releasing the gas above the plants in a sealed room is really the best way to increase your growth and yield with CO2, I have read studies that show a doubling of yields just by increasing CO2.

I do want to end by saying that any CO2 you add should help the plants grow better, so although I can't tell you exactly how many grams you should add, if you add any it is better than nothing. A time release system would be optimal, and then using my article you could add enough CO2 to the room to see big results, but anything you do to improve you growth is good.

I hope this helps, good growing,
Dr. E.R.Myers

E-mail -- Drought Proof Your Outside Plants

2010-07-07T16:24:00.004-05:00

Hello Dr. Myers,
I was reading an old post/ article with your question to the public about how to keep up your plants that you can only tend to once a month or so. I have a few suggestions that you may already know. First, to the best of my knowledge soil conditioned with Humic acid will retain more moisture naturally. I have found this to be true and also have found that plants put in humic conditioned soil tend to take root in the soil faster and bounce back from transplant shock faster as well. I also know that the carbon in the humic acid will feed the microbes in the soil. I am a big fan of the beneficial fungi and bacteria too because they will make the plant more drought resistant. These are all of the natural methods I know of to make plants more drought resistant but one way unnaturally is to add polymers like Soil Moist. I'm not sure if its on the HTGSupply.com web site or not but I have bought it at the Cranberry store and it will retain moisture considerably and slowly release it in the soil over time. This takes a good eye so you don't flood your plants with water for too long so it will be the type of thing that takes some getting used to but it works great.
Thanks
CJ

Thank you CJ for sharing your experiences to help make us all good growers.

Dr. E.R. Myers

E-mail -- pollination

2010-07-04T04:23:00.020-05:00

Happy 4th of July!

I will be posting many past E-mail's this month. I am always happy to get grow questions!!! Please write if any topic is not covered or you want more details about topics you read in past blog posts.

Hi Dr. Myers

You have answered questions from me in the past and I do have another one. In addition to my indoor garden, I have an outdoor vegetable garden. I just recently moved these plants inside my screen-enclosed pool area. Question: Do tomatoes , peppers,etc rely on bees and other insects to pollinate and create the fruit ? So if these vegetables are enclosed..... they will not ever produce fruit because insects and bees cannot get to them..... is this correct ?
thanks in advance

Thanks for your E-mail. I am always happy to help, if I can. You have a good question, the answer is it depends if the plants are self pollinators or cross pollinators. Cross pollinators are plants that produce flowers that are usually big and showy (iris, rose, orchid) commonly the male and female flower parts are contained within the same flower (Link to plant sex parts) but for genetic of physical regions the plant cannot fertilize itself. These plants usually need an insect pollinator or if you are breeding YOU to help them get fertilized. (link to animal vs. plant pollinators) self pollinators do not need an insect or other mechanism to create fruit. Wind pollinated plants put their pollen into the air and it should pass through a screened in area. These plants usually have small flowers, like grass, if you notice your yard gets ‘funny’ things on the tips in the spring or fall, these little ‘things’ are the flowers.

Insect-pollinated vegetables that won't produce fruit well in an enclosed area without your help or insects are: cucumbers, eggplant, gourds, muskmelons, mustard, okra, parsnip, most peppers, pumpkin, rutabaga, squashes, turnips, and watermelon You may want to collect some pollen from some of your pepper plants all the flowers should produce it, and use your finger or a brush etc. and put the pollen from one flower (or better yet from one plant) into another. Look at my past blog posting about how to transfer pollen.

Wind-pollinated vegetables include: beets, chard, all types of corn, and spinach.

Some self-pollinated vegetables safe to grow screened in are: bush and pole beans, lima beans, chicory, endive, lettuce, most peas, and tomatoes. These plants don't need any help they will produce fruit if they get enough light and nutrients.

Good growing,
Dr. E.R. Myers

E-Mail -- Fertilzer and Flowering

2010-07-01T16:23:00.003-05:00

Hello Dr. Myers,
My plants are now ready to be switched to the flowering stage. With so many products on the market, I don't know which flowering formula to use. According to the grow guidelines on htgsupply.com’s website I should use a 10-30-10 ratio? I am growing in soil and using a 400w HPS.

Could you please inform me as to which products (by name) I should use now. Thankx for all your help.

Hello,
Growing in good soil means the fertilizer you use is less important since soil has nutrients in it your plants can use. I know some growers that only use soil and compost and have excellent results. I have not used all the products from HTGSuppy.com so I don't like to recommend specifics. However, I personally use a lot of Fox Farm products, and Hammer Head when my plants are flowering and have no complaints. The ratio from HTGSupply.com is correct, basically, you want to have more phosphorus (middle number) than nitrogen (first number) Some people say to give plants NO nitrogen when flowering but I disagree, plants need nitrogen through all stages of life. You will be fine as long as you give them small amounts of nitrogen and never more as a percentage than P or K. The reason you should not use too much nitrogen during flowering is it tends to promote vegetative growth and in excess will inhibit flowering while phosphorus promotes fruit/flowers. The last number (K) potassium is good for all around plant health and should be given at all stages of plant growth. Sorry I can’t be more specific, but it would be best for you to find what works best for your grow area and your plants. I know Fox Farm products have a good reputation and I have used them for years but there may be other brands that work better for you. If you can, get two fertilizers and use each on 1/2 your plants and see if it makes a difference.

I have shown that too much fertilizer is bad for plants(at bottom of LINK) so do not over do any fertilizer!
Good Growing,
Dr.E.R. Myers

E-mail -- lights to use with indirect sun.

2010-06-29T16:22:00.001-05:00

Hello,
I am growing on a balcony with indirect sunlight. What type of light would you recommend for supplemental lighting? I like the idea of the leds but I have read a lot of articles saying that they are not good for blooming. I enjoyed reading some of your older posts and figured you would be able to answer my question. I know that the hps is the best for flowering and your recommendation if I only buy one light but in south Florida it is really hot and the balcony is about 4' x 8' but the grow area is 3' x 3' so I would rather not use the hot hps.

Hello,
I am always glad to hear people are reading the older stuff.

I think if heat is your big concern an LED or T-5 HO fluorescent would be best for you. The Tri-band from HTGSupply.com is good for flowering and with indirect sunlight you don't need to worry too much about the type or color of light, you are looking more at light intensity (Which the Tri-bands have). There are 50 Watt panels for 139 dollars that might be enough depending on how indirect the sun light is. Go with the Tri-band and do not get an all one color panel. There is also a 120 watt Tri-Band light that will be enough for 3x3 even in a closet. This light is over 400$ though.

The fluorescents are good, and less expensive than LED's but are usually 2 or 4 feet long so that might not fit your 3 foot space needs.

Good Growing,
Dr. E.R. Myers

E-mail -- How Close to Put HPS for Clones

2010-06-21T16:22:00.004-05:00

Dr. E.R. Myers
I just bought one of your 400 hps lights.....things are looking good.....I'm curious as to how close is normally a good distance to my vegging clones....they are a few weeks rooted...I know it's too close if they burn (grin) I just wonder how close do people run 'em?? Thanks

Hello,

The heat is the real problem. If you have a light fan blowing over the plants or an air cooled light you can keep the HPS within 2 feet. I usually keep My 400 HPS light about 3 feet above the plants that I grow.

Do you use the HPS as your only light? This is ok, as I have written about before but... I usually recommend a fluorscent for early cuttings and seedlings. The HPS will also decrease the humidity in the room which is good for flowering (no mold) but not good for vegetative cuttings which need a moist environment for the first couple weeks. Do you have a thermometer with min/max and humidity readings? That is a good tool to have and will let you know if you need to adjust things to maximize growth. A good rule of thumb is if your temps. are in the 90’s and higher by the plant tops, move the light up. If you can’t get the temperature below 90, you need to ventilate the room or switch to LED or fluorescents.
I hope this helps,

Good growing,
Dr. E.R. Myers

NINE STEPS TO A SUCCESSFUL TRANSPLANT

2010-06-17T16:22:00.002-05:00

I will finish this potting up segment with a top 9 list. I guess I could make it a top 10 by saying 10) ENJOY YOUR PLANTS, but I assume everyone does that already.

1) First, you should water your future transplants with a good transplanting fertilizer high in phosphorus and with vitamin B1 two days before you transplant.

2) Fill your container, or pot, with potting soil or whatever medium you grow in, you will want to makes sure the plant will be at the same height in the new pot. In other words roots should not be exposed and you should not burry excess stem. An acceptation is tomato’s and potato’s which will happily put out new roots if you burry the stem. Most other plants will be susceptible to stem rot if you burry the stem.

3) Saturate the medium you will transplant into with water mixed with transplanting fertilizer. Make sure the soil is completely saturated with your water-fertilizer solution, leaving no pockets of dry soil. If you don’t saturate all the soil you could have pockets of dry soil that future roots won’t be able to use, and therefore you will be wasting space.

4) In the container in which you are going to place your transplant, dig out a hole the approximate size of the container from which your transplant will come. I like to use the starter plugs for germination and cuttings, they make potting up a lot easier.

5) If you have bigger plants in pots you may need to roll the old pot in your hand or on a table to loosen the dirt and roots from the side of the container. (Be careful you don’t damage the plant in the process of loosening the roots!) Next, grasp the base of the plant, turn the container upside down, and pull the root ball out, being careful to keep the roots in one piece. I like to tap on the bottom to help the plant come out of the container.

6) Carefully place the root ball in the hole in your prepared container.

7) Now that the root ball is in place, you can fill in the space around it placing soil gently, but firmly around the top of the roots. No roots should be exposed and you should not burry excess stem. Make sure that all the roots are pointing down. A trick I learned is to put the plant in the hole a bit deep and then after adding some soil pull it up gently by the stem. This will make sure all roots are pointing down. You then pack down and add more medium to keep the plant upright.

8) With your transplant in its new container, water the plant once again, lightly, with your fertilizer solution. Make sure the soil is saturated, but not soggy. Keep the soil well watered, but make sure that the plant has good drainage and is not in standing water

9) Place your new transplants in low light conditions. I think fluorescents are best. If you don’t have any you should raise your HID or LED several feet higher than normal. The transplants should be able to handle full sun or HID light within a day or two.

If your plants outgrow their new containers, simply follow these 9, steps again to transplant to a larger container.

Good Growing
Dr. E.R. Myers

Containers and Potting Up

2010-06-14T04:23:00.007-05:00

Potting-up" is just the term for moving seedlings out of the seedling tray or small container and into a larger container--

First, gather up enough pots so you have one for each plant. You can re-use pots that you may have lying around, just clean them with soap and water first. If you have had infestations make sure you disinfect them using a weak hydrogen peroxide or bleach solution and rinse them completely before planting in them. You can also find new, clean pots at HTGSupply.com. I like to use plastic party cups for small plants, they are cheap easy to get and can be disposed of after one use if you have pest or disease problems. I have reused plastic cups many times when I am not bothered by infestations.

You will also need several large, water-tight trays that the pots will fit into to catch the excess water that runs out of the pots. I clean, disinfect and re-use trays from year to year.

If you have problems with fungus do not splash water on the plants by watering the trays and let the water soak up into the medium. You should not let your plants sit in water more than 24 hrs.

Good Growing,
Dr. E.R. Myers

PRECAUTIONS AND TIPS ON TRANSPLANTING YOUR PLANTS

2010-06-06T04:24:00.001-05:00

When the roots of your plants have begun to outgrow their containers, it is time for your plants to be transplanted (Potted up). Potting up is necessary to allow your plant's roots to continue to grow, and is therefore a necessity for the overall health of your plants. When a plant becomes root bound (when the roots don’t have any medium to grow in) it can result in, slow growth and unhealthy plants, basically not good growing.
Transplanting can be a traumatic experience for your plants and there are precautions you should take to ensure success.
You should transplant when several roots start to stick out the bottom of your container. You should not do this too often but if you wait too long it can cause stunted or no growth, reduced yield, and increased disease susceptibility to name a few.
During potting up you should disturb the root system as little as possible. Even if you are very careful after transplanting you may have damaged the roots, so it will be hard for plants to take in water until new roots begin to grow. You should water your plants and keep the medium moist. It may also be a good idea to water your plants with a good water-soluble fertilizer that is intended for transplants. I have recommended fertilizers with Vitamin B1, like Hormex (always read and follow mixing instructions). After transplanting, your plants will need time to adjust and re-establish their root systems. They need low levels of nitrogen and potassium but will require large quantities of phosphorous. Also, studies have shown that a weak sugar and water solution made with plain sugar from the grocery store given to a plant after transplanting can reduce transplant shock in plants. It only helped with some plant species, but adding a teaspoon per gallon of sugar will not harm any plant, it is worth a try. The reasoning is that plants use sugars just like you and I. They usually make their sugars with photosynthesis but with limited water uptake from transplanting, giving your plants some extra ‘energy’ may help them keep growing or recover faster. If you give the plants sugar I suggest unrefined sugar if you can find it but try others there are many types of sugars, they all end in –OSE – sucrose, fructose, glucose, dextrose, maltose etc. are all sugars. (Now go read the back of your favorite cereal and see how much sugar it has.)

During the period after transplantation, your plant will have a reduced ability to absorb water and nutrients at first, and as a result they should have subdued light. I think fluorescents are best for this and that the HID is too intense. I think you could use an LED like the Tri-Band from HTGSupply.com if you kept it a few feet above the plants. (see my previous posts on growing with LED) I have begun to think that LED’s could be good for seedlings - with their low heat and high light output they can be placed high above the seedlings and cover a very large area compared to a fluorescent.

I have also read that people recommend you transplant late in the lights on cycle to give the plants all night to recover. You should also make sure the pot you are transplanting into is large enough for the roots of your transplants to grow and expand in. Growing indoors means you may have to grow in a small space so you want to keep the plants in containers that fit the space and the plant

You may come across articles that say while translating you should trim back the plant – I do not do this, I just can’t accept that cutting off leaves is good for a plant. Leaves are where the plants do photosynthesis so they provide energy to the plants. The logic with trimming is that if you remove the leaves this is less area for water loss and the plant won’t need as much water until the roots can grow. I would wager that trimming back the plants means you loose out on yields and over all growth later on, but I can’t back that up with an experiment yet. If you keep the roots in tact you should not have much of a problem. If you are transplanting a plant from say outdoors where you may not be able to get all the roots, THEN maybe I would recommend cutting back the plant so it does not die due to dehydration.

When the root systems are disturbed little, fertilizer is properly applied, and light is kept at a minimum for a few days your plants should show few signs of transplanting shock, or wilting.

Good Growing,
Dr. E.R. Myers

E-mail - white roots coming out of pot

2010-05-28T04:22:00.003-05:00

Hey doc,

I have some plants growing and noticed the roots were starting to come out of the bottom drain holes of my pots. Some even have a white fuzz growing on them. Are my plants going to be able to grow ok, and how do I solve this problem?

Hello,
Your plants are getting big for the pots/ container they are in. If your plants are already well into flowering or making fruit you can just keep them in the same pots and make sure they are well watered (not over watered) until the plants are done. The idea is to keep the roots moist and alive and NOT dead from being dry or in standing water. Growing in small containers can be done but it requires more attention to detail, similar to hydroponics. I suggest you don’t transplant them if it is late in flowering because this may stress out the plants which causes poor flowering/fruit set. Next time you grow put the plants in bigger pots. Unless you are confined to a small space you should give your plants all the room to grow they need.

If your plants are growing vegetativly, you just need to pot them up (put them in the next size pot). I’ll be posting about potting up in the next week or so. If you just have one root coming through you can wait a few more days to pot up. If your plants look like the picture below, pot them up today.
The white fuzz is good; it is most likely root hairs. Often on the end of roots you find a lot of small little hairs that stick out to give the roots more surface area so that they can absorb water and nutrients more efficiently. White roots are healthy and growing, even more so if they look fuzzy. If you don't put the plants in a new pot the roots will turn brown or tan. This is not necessarily bad but w/out any more space for roots to grow, you plants won't grow or flower at their best.

Good Growing,
Dr. E.R. Myers

E-mail HOW LONG DO MH AND HPS LAMPS LAST? and LED

2010-05-22T16:22:00.011-05:00

HEY DOC,
HOW LONG DO MH AND HPS LAMPS LAST?

Hello, I have talked about this in a few posts but it would be good to have all the info. in one place, thanks for your question.
I assume you mean how long do the bulbs last; the ballast will last for many many years. I should say this is outside my area of expertise (which is growing plants) and you should send an E-mail to Sales@htgsupply.com. Perry the manager will be able to answer your question better than me. However I have used a lot of lights so I will give you my input too.

Most bulbs sold have a “rated life” that is stated on the carton or the literature. It is my understanding that rated life refers to the point at which 50% of the lamps in a large sample will be “burned out". This is not the end of the story, you should know there is a depreciation i.e. lower light output as bulbs age. Another factor to know is that the more you turn on and off your HID the shorter the rated life. You can tell a bulb is done when it starts to cycle on and off when the light should be ‘ON’.

I will assume you are using the HID for flowering and the light is on for only 12 hours a day. If you use the HID for vegetative growth and flowering your lights will have a shorter life then what I suggest. I would use LED or fluorescent lights for seedlings and young plants and leave those lights on 24 hrs. a day to speed of the growth rate. When you begin to flower you should know most HPS lamps have a rated life of at least 24,000 hours (over 5 years of flowering). Most MH lamps have a rated life of 10,000-20,000 hours. (2-4 years of flowering). HOWEVER, since all MH and HPS bulbs will slowly “depreciate” (decrease in light output) over time, good growers replace the bulb long before the light output declines significantly. I don't recommend using an HPS bulb more than 2-3 years and an MH more than one year. I say this because your indoor garden yields are so closely tied to light output, and a 50% decrease in light output may result in a 50% decrease in yields. An HPS lamp will lose approximately 20% of its light output before it reaches its rated life while an MH lamp may lose up to 50% of its light output before it reaches its rated life. A MH will depreciate at a faster rate than an HPS. If your MH bulb is over two years old you may increase yield by 50% just by buying a new bulb. I always recommend keeping one old bulb (the one with the least hours) as a back up. I say this in case you have an accident and you break a bulb, your plants will need light with in 24 hrs, but some of you are 2-3 days from the nearest HTGSupply.com store or receiving a bulb by mail service.

You did not mention LED's but after my posts about growing with LED I want to include them as a viable choice for growing indoors or in small spaces. An LED like the Tri-Band has a rated life of 100,000 hours and has almost no depreciation. (That is 22 years flowering). If heat and / or electricity usage are a concern or you are thinking about growing for a long time, you should look at the Tri-Band LED from Htgsupply.com. You could use it in any grow set up but I used it in a grow tent with much success.

Good Growing,
Dr. E.R. Myers