Small Spaces and Containers – Maximizing Growth and Yield

Pot up early and often for maximum growth and yield
In a post in 2009 I  posted pictures where I compared plants in various sized containers, and put different numbers of plants in containers.  Smaller containers result in smaller plants and smaller yields.   Multiple plants in containers lead to smaller plants and smaller yields too.  The trick is getting the smallest sized container that will allow your plants their maximum growth in the space you have indoors.  A rule I have read is one gallon of soil/medium for each foot of plant height.  This of course depends on the species of plant you are growing, but is a good rule of thumb. 
I have noticed another problem with small containers.  Many growers start several plants in small containers and then put them up into bigger containers as they grow.  This is a good way to pick the best plants too, especially if you are doing any plant breeding.  Remember; if you breed plants don’t get mired in mediocrity.   If you keep a plant in a small container, and it gets root bound, even when you pot up the plant it will not grow to its fullest potential.
The take away message, always keep your plants roots growing.  Once the roots start to twist around and around in a container, they send out hormones to the plant that resources are going to be limited, and growth should slow.  When you pot up the plants, they will grow more, however not as much or as big as plants that were never root bound.
You should pot up your plants as early as possible.  Here is what I noticed this semester; I had two groups of plants.  Group one, I potted up as soon as roots got to the bottom of the container.  I started with small containers, then went up to one gallon then three gallon containers when I put them onto flowering.   The second group, I kept in small containers for an extra two weeks, then put them in one gallon containers for two weeks longer than the first group.  My idea was that I could get two flowering cycles in one semester.  What I noticed is that the first group plants were all tall and bushy and the second group plants were shorter and single stemmed.  It seems that when a plants roots are not allowed to grow, the hormones that slow growth somehow prevent the plant from ever reaching its full potential.  I think this would be like if a child does not get all its nutrition, it will never be able to reach its full potential, even if has all its nutrition met as an adult.

Pot up early and often for maximum growth and yield
Good Growing,
Dr. E.R. Myers

Read my post on suggested container sizes for plants


Upgradeing Lights in the Mother Keep Grow Tent

Hi doc, looking to change out my lighting setup to something new.
I'm running t5 four bulbs 4 feet long which came with the motherkeepergrow tent from htgsupply.com.
I veg/flower in the same tent, but would like a stronger light for flowering only and not sure what to use. I’m sure 1000 watt lights would burn my  tent.

Just looking for ideas I have five plants only.  Thank u

  You could get a 1000 Watt with ductwork andventilation, they have lights where the bulb is encased in glass connected to the duct work, and plants can grow almost right up to the bulb.  But, if you switch to an HPS, you may run out of room because your plants will probably get taller than they did under the T5.  So, if I were you, I'd get an LED.   You may want to get two 135 W LED's and put them in the grow tent about 2-3 feet apart.  I love the T-5's and use them to start my plants, but your plants will really flower better under an LED.  Get a 7 band, not a single color LED.  I think you'd be better with two smaller LED's than one big one, unless you wanted to also get a light mover but that might take away from some of your space.
I hope this helps.
Good growing
Dr. E.R. Myers


Pruning Plant Tops - Plant Hormones and Plant Growth Patterns.

If you read my post on how plants grow, you know that most plants (other than grasses) grow from the top, (specifically in an area called the apical meristem) and I mentioned in this post  some ways this knowledge can help you be a good grower.  There are other ways this knowledge can help with plant growth.  The apical meristem (link to plant growth article) is also where many hormones are created/secreted.  If you cut  off the top of a plant, most of you know the plant will get bushier.  I often do not recommend doing this*, as it stresses the plant to have its apical meristem removed.  Cutting plant tops can be necessary with some growth methods (read my post on the sea of green technique). 
The physiological reason why plants get bushier when the top is cut off or bent is that one of the hormones that will be no longer made by cutting the top of the plant used to prevent the branches from growing, this is termed apical dominance.  Without the plant top, the branches will be grow at an increased rate from their meristem tissue, termed secondary meristems.  This means each branch will elongate, and each branch will secrete more hormones.  In some plants, one of the branches will become ‘dominant’ and suppress growth of the rest of the plants, making the plant start to grow tall again.  Other plants will just become bushy and will have lessgrowth in height.
Good growing,
Dr. E.R. Myers

* I more often recommend bending the top of the plant, this will slow the hormones, and make the plant more bushy (less tall) without the stress of recovering from cutting off the top.  The benefit is that bending  does not result in several days where the plants do not grow because the apical meristem was lost and the growth hormones, are gone.



The Down Side of LED’s

If you have read my blog from the beginning, you know I’ve gone from thinking the best light is an HPS, to using LED’s and loving them.  The intensity of the tri-band and seven-band LED’s from HTGSupply.com have proven to be awesome at growing plants indoors.
No one light is going to be the best for everyone everywhere.  A friend of mine has a detached garage, and I helped him put in a 10x10 grow room in the garage.  The garage gets hot in the summer, and he is thinking about putting in an A/C unit.  I suggested he just grow outdoors in the summer and save electricity.   I also suggested when he wanted to try something different he use LED’s instead of the 1000 W HPS he had.  The plants are growing great.  However, what he’s noticed as the weather gets colder is that the often unwanted heat of the HPS was needed in the grow room.  The HPS was run at night, and keept the grow room in the 60’s on cold nights.  This week he noticed that the room was getting down into the 40’s when it was in the teens.  40’s won’t kill plants, but it can stress them out, and will really slow down growth.  Worst of all, winter is just getting started.  So, if you are in a situation where the heat from an HID is necessary to keep the room warm in the winter, then you may not want to switch to an LED.
Good growing,
Dr. E.R. Myers


Did Day Light Savings Change Your Prefered Light Cycle?

If daylight savings changed your light cycle, and you want to change it back, it is better to have a longer night than a longer day if your plants are flowering.

Click here to read my post on how best to switch your plants after daylight savings

Good Growing,
Dr. E.R. Myers


Drying Herbs

In my post in 2009 about drying herbs I mentioned you could quickly dry herbs with fans, and in fact air movement is important to prevent mold, but that slow drying often brings out the full flavor.  I want to expand on this, due to an E-mail I got from a reader.  He suggested that the slower the herbs dry, the better for the flavor.  He recommended putting the herbs in a Tupperware container after 2-3 days with the lid on but NOT sealed.  Open the lid in a couple hours, if the herbs seem wetter, keep the lid off.  After a day or two, put the Tupperware lid on tight on one corner (always make sure the herbs feel dry when doing this, if they feel wet, you will have mold).  Open the lid a couple times a day and feel the herbs.  When they are completely dry (I keep a stem in with them and when it snaps easily, and does not bend, the herbs are dry) seal the lid and store the herbs
Read my post on Herb Storage
 I concur with this slow drying.  In fact, even though plants are technically dead when you cut them, there are physiological reactions for many hours, and chemical reactions for days.  Once the water content becomes very low, most chemical reactions and all biological ones will stop.  By slow drying, you allow for the molecules in the plant cells to interact completely.  Now, the fun thing for me about biology is that there are always exceptions.  So, some plants you might want to dry quicker than others.  The best way to test this is with a scientific experiment.  Have two or more types of drying techniques with not just the same herb, but the same plant.  
Good Growing,
Dr. E.R. Myers


Create an Environment For Fast Germination and Maximum Seedling Growth.

Now that fall is upon us, and for most of us the outdoor growing season is done, or will be done soon, it is time to concentrate on our indoor garden.   I always encourage my readers, and students to try new things in a scientific manner.  This can be done if you are growing multiple plants in multiple containers, simply treat a group of pots one way, and compare them to the group(s) that you treated differently.  Hydroponic systems that share a reservoir do not lend themselves to this type of experiment.  However, with careful notes and measurements, you could compare one growing season to another where you tried something new.

With seed germination, you want to create a warm, moist environment.  I’ve hear many a gardener say to put germinating seeds on top of the refrigerator because this is a warm spot in the house.  That is free, and ok, but the AgroMax Heat Mats sold by HTGSupply.com are perfect for increasing germination.  You do not want hot, that can actually kill your tender young seedlings, so never use an electric heating pad, or put the seedlings in an area above 90F.  The heat mat heat raises the temperature a few degrees above room temperature.  You can use any medium for your seedlings, but as I’ve said, I really like the starter plugs.  You can also put seeds on a moist paper towel in a baggie and put the baggie on the heat mat
    With the heat mat, you should see seed germination in a few days.  If you are using the starter plugs, or if you put your seeds in soil etc. to germinate them, you have a week or two before you need to do anything.   I would keep the light on 24/7 for the first few weeks to maximize growth.  After a month, I switch to 18 on 6 off until I induce flowering.  If you are doing your germination on a paper towel you need to get the plant into the medium asap as soon as you see the root coming out of the seed.  There are no nutrients on the paper towel, and I have found you get mold if you do use fertilizers on the paper towel.  Moreover, the small roots are delicate, and if you break off the root tip when you plant your seedling, you just killed you plant, or at best set it back a week or two in growth.
   You will want to keep the light a bit higher (1 foot or so) for seedlings than mature or flowering plants.  Too much light can stress out a young tender seedling.  After a week, you should see growth and you can lower the light and start to use fertilizer (I usually recommend ½ strength for the first 1-2 watering’s.)  You are well on your way to a successful growing season indoors…
Good Growing,
 Dr. E.R. Myers


How to Tell if Your Plants Are Growing at Their Maximum

Look at your plants.  Do you notice that the top leaves are small and seem not to be growing?   The plant can look healthy, but are the leaves on the branches growing?  For most fast growing plants grown indoors under a light from HTGSupply.com, you should see changes in growth every day.  If your plant seems to be stuck, your plant may be root bound. (click here to see pictures of a test I ran on pot size)
Even if you do not notice slowed growth, good growers know that when you harvest your plant, you should take a look at the roots.  If you see a white ball of roots and no soil at the bottom, or the roots are in the shape of your container try a bigger container next time.  When plants roots get compressed in a small pot, the plant will grow smaller and have less yields, as well as be more susceptible to fungal infestation and other diseases.
Good Growing,
Dr. E.R. Myers


What to do Between Vegetative Growth and Flowering

Good growers know that when plants are in different phases of their life cycle (seedlings, vegetative growth and flowering) they have different nutrient requirements. 
Read my post on how to improve flowering
If you just read the above post, you know you want to reduce nitrogen, but not eliminate it when your plants are in flowering phase.  All living things need nitrogen, and plants are no acceptation.  Many fertilizers labeled “For Improved Flowering” have no nitrogen, and I think this is a mistake.  Nitrogen is used by plants in all phases of the life cycle.  While nitrogen promotes vegetative growth in large quantities eliminating it will slow growth, and lower yields.  Everything in Biology follows the Goldilocks principle, not too much, not too little, just the right amount.  When my plants are flowering, I use a fertilizer that has a low number for nitrogen, like Big Swellwhich is 2-5-7.    
If plants are green, healthy looking and over all doing well when you alter lights for flowering) just use something like Big Swell2-5-7.  If you have brown leaf tips, stretching nodes, and reduced root growth you may have a lot of nitrogen and you should use something like Big Bud which contains no nitrogen after the plants dry out from  thoroughly  being watered with pure water.  After this, I'd go with a now nitrogen fertilizer for the rest of the flowering cycle.  Hydroponics like soil growers should always provide some nitrogen to their plants.  It is normal that yellowing should start to occur in flowering, this is a sign the plants are focusing on flowering, not making new leaves.  Be sure to give the plant a bit of nitrogen to keep it growing well through the flowering phase, which for most of us, is the most important part of plant growth.
Good Growing,
Dr. E.R. Myers


Fungus in the Grow Room

I get a few E-mail’s about fungal problems.   Many times I am not sure if it is fungus, or a phosphorus deficiency.  The leaves at the bottom would get brown/grey and dry and shrivel up.  I usually ask about phosphorus, but most people use too much nutrients, not too little.  I then recommend adding some lime to the water to adjust the pH, thinking maybe if the soil pH was too high, the phosphorus would not be absorbed.  It seemed the plants would limp along and people would eke out a small harvest.  I know most people would be happy to get anything when it looked like the plants were going to die, but after a second and third time, it is time to get this problem under control.

Air flow and lowering the humidity are too very important ways to reduce fungus.  Another very important factor is making sure the plants are growing in good soil, I like to add perlite or sand to most mixes I buy.  This allows the roots to grow.  Healthy growing roots send a message to the top of the plant to keep growing, nutrients and water are on the way.  If your plants are root bound, they will be more susceptible to disease and fungus. (read my post on potting up) If those environmental measures don’t keep the fungus away, you can try using Serenade.  I have used it and it works. 
Click here to read about fungus and cuttings

Click here to read more about fungal prevention

Please E-mail me with any questions or comments

Dr. E.R. Myers


E-mail - Is a LED the Right Light?

I am in need of a grow light.  I had bought a 90W 3 band ufo on another site claiming to out preform a 400W HID and cover a 4x4 area, but after several months I am very unimpressed.  HTG recently recommended the 430W 7 band LED as being able to cover a 4x3 area.  This seems to mean to cover the same size area I could either run a 400W MH (which I already have a ballast) or the 430W LED.  I switched to LED in the first place because my utility provider is very expensive compared to others around.  Currently what do you believe would be the best option?  In several of your old posts you recommended the tri band LEDs, but why not the 7 band?  I will need to ventilate either way so that is not an issue.  The HID lights are much cheaper, so what makes the LEDs so much better aside from longer life.  I want the ability to cover about a 4x4 area, but be as energy efficient as possible.  What are your thoughts?
I agree with your thinking.  The LED, will cover that area, you can keep it 3 feet or a bit higher above the plants to cover more space.  White walls will be your best bet to increase reflection; don't forget to paint the inside of the door too.

The 7 Band 430 watt LED  uses about the same electricity, as a 400 w MH but the LED will grow plants great.  If energy conservation is a priority, you could get away with a 240 watt LED, but you might not be able to fill all your grow area. I can tell you any LED from HTGSupply.com will be better than a MH, especially if you are going to flower your plants.   With a MH or HPS, you will need to replace the bulbs every couple years, if you want to get the most from the lights.  LED's don't have this problem; they last for 80,000 or more hours with little to no loss of output.  So, the LED will save you on electricity and will give you great plant growth for years without having to spend any more money on bulbs.
I hope this helps, E-mail me with any more questions,
Good growing,
Dr. E.R. Myers


Plant Dermal Tissue – Stomata, Root Hairs and Trichomes

Plants like all complex life on earth are organisms, made up of organs.  Leaves, stems, roots and flowers and fruits are organs found in plant which are made up of tissues.  Tissues are just made up of a combination of cells working together.  The tissue types found in plants are ground tissue, dermal tissue and vascular tissue.    Ground tissue is where cells that do the basic plant metabolism are found. Vascular tissue is where cells form tubes to transport material around the plant, much like our veins, arteries and capillaries.  The dermal tissue is the outer layer of the plant.  Most plants have a waxy layer called a cuticle that protects the plant from UV damage, prevents dehydration and can help protect from predation.  Under the cuticle, in the epidermis we find some specialized cells.  Guard cells are specialized cells found in pairs.  The opening between the guard cells is called a stoma (stomata is plural).  The stomata are where plants take in CO2, and release H2O generated during photosynthesis.  Many plants have a lot of stomata under the leaf, and indoors without rain, you may find increased plant growth if you mist or apply foliar spray to the leaves to rinse the dust out of the stomata.  However, mold can also benefit from foliar sprays, if you are only growing plants indoors under a light, and they only live a few months, you might not need to clean out the stomata, but if you have plants indoors that are year’s old, maybe spring cleaning should include a shower for your plants.

Other outgrowths of the dermal tissue are trichomes and root hairs.  Root hairs occur below ground, and are very important to plants because the root hairs increase the surface area of the roots, increasing water and nutrient uptake.  Many beneficial bacteria and mycorrhiza fungi are actually smaller than root hairs, so they increase nutrient and water uptake.  Your roots should be white and‘fuzzy’ if your plants are healthy, the fuzzyness is the root hairs seeking water and nutrients for your plant. Root hairs usually only last for 2 to 3 weeks and then die off.  This means you will find healthy root hairs at the ends of your roots, which makes sense, since the plant may have used up nutrients around the old root hairs.  The take away message   is that you want to minimize damage when potting up, which is one reason I recommend using the starter plugs vs. just plain sol for seedlings.
Trichomes are a general term for outgrowths that occur on the stem and/or leaves.  I could write many posts about the different kinds of trichomes.   In many plants these little ‘hairs’ help plants regulate water and heat loss.  They can also help with predation with both small and even large herbivores.  In some plants substances are secretedseveral basic functions or advantages of having surface hairs can be listed.  Studies of trichomes on plants subjected to frost show the ‘hairs’ keep the frost away from the living surface cells.   Other studies show that dense coatings of “hairs” reflect solar radiation, protecting the more delicate tissues underneath
Good Growing,
 Dr. E.R. Myers


How to Get Cloning Success for 20 Generations and Counting…

Do you know about the first mammal ever cloned?  The sheep they names Dolly.  Dolly was just one of many attempts to clone a sheep, she was the first that survived.  It was heralded as great success.  However, many people do not know the end of the story,  Dolly had to be euthanized when she was only 6 (sheep live to 10-12 commonly)  The problem was she was suffering from geriatric diseases.  The problem with cloning is that cells keep track of your age, so if you clone a 5 year old sheep, its cells will know, and act, like they are 5 years old the day it is born.  This limits animal cloning today, since you need to wait for an animal to mature to know if it has the characteristics you want in the clones.  The same is true for plants, the cells know how old they are.

Good growers know that you can only clone a plant so many times.  Many scientific publications have shown as few as 5 times are possible to get a plant to clone without changes in growth, yield etc.   I have a friend that has cloned her plants over 20 times, and has no noticeable difference.   Here is the trick...  Plants measure days in light and dark cycle, with a substance called phytochrome, (click here to read a post about phytochrome and plant flowering)  so it would make sense that a plant that was kept on 24 hours of light might think it was one day old.  This would make a HUGE difference in cloning longevity compared to growers that use an 18/6 light cycle.   A plant on 18/6 will be a month or more old when you clone it, (it will have had 30 days and 30 nights) and if its offspring are cloned using 18/6 they will add another month to the age.  After a few generations of cloning, the plants will think it is a year old, which for annuals means they will start to show growth abnormalities and have reduced yield etc.  Compare this with a plant that was on 24/7 for a month, it might think it is only a single day old!  If the next generation are then put on a 24/0 light and then cloned, the plants would be two days old.  This could be a way to have cloning work for maybe 100’s of generations. My friend is at 20 and counting with no signs of problems.  If any readers have any input, on this topic, please let me know.
Good Growing,
Dr. E.R. Myers

Click here if you'd like to order clonex which will also help improve your cloning success


Plant Knowledge to Make You a Better Grower – Plant Growth

Good growers are observant, and learn everything they can about the plants they grow.  There is an incredible amount of plant diversity, and as more and more people grow indoors and out, the types and varieties of plants that people will grow will increase.  There are certain aspects of plants that are the same for all plants.  Larger plants are usually termed vascular plants, because like us, they have veins that move water, nutrients and waste products around the plant.  Mosses are examples of plants that do not have veins.  The lack of veins means that non-vascular plants are limited in size because water has to diffuse through the plant to get to all the living cells.

Vascular plants only grow in certain areas called meristems.   The meristems are areas where cells divide, one cell splits into two cells, one of the cells can become specialized into a root, stem, leaf, or vein tissue, the other can be divide again forming another specialized cell.  Meristem cells act like stem cells in animals. 

Primary growth is how plants get taller.  This occurs in the apical meristem.  The apical meristem for most plants is at the top of the plant, so most plants grow from the top.  Plants do not grow like you and me, if we grew like plants, we'd only grow from the head up.  An exception to this is grass.  Grasses are one of the most widespread plants, found on 6 continents because they grow from the bottom.  This means that grazing and mowing do not damage the apical meristem, and the grass can grow back.  How well would a rose or oak tree do if you mowed it each week like a yard?  ** Here is the take away message** Since the tops of your plants are where new growth will occur, make sure you do not burn the tops of your plants with lights.  This is one of the most important areas of the plant so you want to protect it.  To do this you want to take the temperature of your plants at the tops.  It is in the tops of your plants where most of the metabolic activity is taking place, so you want the temperature and humidity to be optimal at the tops.  I use a thermometer with a separate cord and I put it at the top of the grow area, where it is usually hottest, and I hang the secondary cord down and lay it on the stem at the top of my plants so I know what the temperature is at the plant tops.  Most plants do well with temperatures in the low 80’s, and some people say upper 70’s gives even better growth.  You can figure that out for yourself with your plants in your grow area.

Woody plants get thicker by secondary growth.  Secondary growth or thickness occurs in lateral meristems.  This is a tube like area on the stems were cells divide outward increasing the girth of the plant.  I will be talking about plant organs in future posts, leaves, stems, roots and flowers/fruits.  Until then….

Good Growing,
Dr. E.R. Myers


E-mail - Slugs in the Grow Tent!

I have a grow tent in my garage.  I found slugs in my grow tent, what do you recommend as I plan to eat my plants, so I don't want to use anything toxic.  I am growing in a soil mix I got from HTG

  The slugs are getting in from somewhere, you may have a small hole etc. in your garage.  They are most likely nocturnal, so you could go out at night with a flashlight and look for them.  Also, slugs leave a slime trail, which helps them move, but it also allows them to find their way back to the food, look for a slime trail coming out of your grow tent and you might be able to follow it to where they are getting in.

Slugs are easy to control, you just have to sprinkle sluggo all around the grow tent.  This is made of iron phosphate, so you can put it in the soil around your plants, and even around the outside of your garage.  Just make sure you put a lot of it down, you want to make sure the slugs crawl over it.  The sluggo will be absorbed by the slugs, and it interferes with an enzyme in their digestive system and they no longer can eat, and they die.
I have written a post about slugs and snails with pictures of damage, if click here if you want to see it.
Good growing,
Dr. E.R. Myers

Click here to order Sluggo!

Here is a picture of a leopard slug, it does not have its antennae extended.


E-mail LED and Vegetative Growth

I've just purchased this LED from HTG Supply.  It's a 90w with 3 color wavelengths (red 630-660), (blue 450-460) and (orange 610-615).  I'm using it with 4 plants (clones) for 12 hours a day with the light 1.5 meters above the plants.  After 2 weeks using this light, I'm seeing minor amounts of flower initiation.  I've increased the light to 16 hours a day now but have a lingering question....is there a problem with using this 3 color LED light during the plant growth phase?  It seems to be a great light for my application.  Thanks- 

 You are growing a short day plant. (Read my post on Plantflowering) If you want to make sure the plants do not flower anymore, you could leave the light on 24/7 for a couple days, or take the length of the day (time light is on) to 20 hours.  Read my post on speeding up flowering
If you got the LED from HTGSupply.com, then you are fine for all growth phases.  Plants need red and blue and some secondary colors to grow.  Blue light is associated with vegetative growth, and red with flowering, and your LED has both.  I have found that the LED's keep the plants growing short and stocky during vegetative growth phase just like when I used fluorescents and plants flower as good as with an HPS
So, you are fine.  Let me know how things turn out with your LED.
Good Growing,
Dr. E.R. Myers 



The Right Length of Day To Make Your Plant Flower

 To understand plant flowering, you need to understand a term "photoperiodism," which is the amount of light and darkness a plant is exposed to. The amount of uninterrupted darkness is what determines the formation of flowers on most types of plants.  Uninterrupted is bold because this is very important.  When growing indoors you want to make sure your grow area is light proof or you may not get any or very poor flowering.  Some growers  think that the length of daylight a plant is exposed to determines when a plant flowers.  However, scientific experiments proved otherwise. It is the length of darkness that a plant experiences that plays the most crucial role.

A plant that requires a long period of darkness, is termed a "short day" (long night) plant. Short-day plants form flowers only when day length is less than about 12 hours. Many spring and fall flowering plants are short day plants, including some strawberries and Christmas cactus. If these are exposed to more than 12 hours of light per day, they won’t flower.

Other plants require only a short night to flower. These are termed "long day" plants. These bloom only when they receive more than 12 hours of light. Many of our summer blooming flowers and garden vegetables are long day plants, such as, lettuce, spinach and potatoes. These all bloom when the days are long.  And some plants form flowers regardless of day length. Botanists call these "day neutral" plants. Tomatoes, corn, cucumbers and some strawberries are day-neutral.
You can do an internet search for the plant you grow to see if it is a short day, long day or day neutral plant.
Good Growing,
Dr. E.R. Myers


E-mail - Grow Tent with LED in Garage

Thanks Doc for all of the great information, my grow tent is located in the garage and so the humidity levels can get rather high. I also had opened the lower screened vent flap in hopes that I could pull in some fresh air but now thinking about it, all I am doing is letting more humidity in. I did run my fan all day and was able to get the humidity down to 71% (10pt drop) and the indoor temp was at 85 degrees. I'll keep monitoring the levels and see what happens. my readings this morning were 84/64 which is a whole lot better. I think the readings yesterday were about 88/72 +/-

Another question that I had was about the light intensities of the Led Lamp. I have a 120watt Tri-Band Led that has a dimmer on it. I had run the lamp at full intensity at first but was getting what I was considering "High" temps near 90 degrees so I dialed back the intensity of the lamp to finally where I was yesterday, 81 degrees and 81% humidity. I then turned up the intensity to the lamp and turned on the fan and was able to get much better readings.(85/71) So here's my plan, close the screened vent at floor, run high intensity, run fan and watch my watering. What are your thoughts?
You should keep the LED 2-3 feet above your plants and I'd recommend keeping it at the maximum intensity if you can, this will maximize growth and yields.  I only use a dimmer for a carbon filter, if you are growing in a smaller room, you can use the dimmer to have the fan blow less and the filter last longer.
Are you using a thermometer with a min. max setting?  I ask because I was growing some plants up in an attic once.  I had the lights on during the night since I figured it got hot during the day.  Every evening I'd go up and check on the plants, and the temperature was in the 80's or low 90's, high but ok.  The plants were not growing well, they were stretching between nodes and had big odd shaped leaves.  I put a thermometer up there and realized on sunny days, the attic temperature in the afternoon with the lights off was over 130F.  That is too high, and I had to move the plants to a new location. I was only checking a regular thermometer in the evening after it cooled off.

Now, if you are concerned about humidity and temperatures you can get a thermometer/barometer with a sensor to get your fan to turn on when the temperature goes over 85, and the humidity goes over 60, I would highly recommend that.  If you do not have problems though, you do not really need to do anything.

Good Growing,
Dr. E.R. Myers


E-mail - LED, Grow tents, humidity and temperature

Hi Doc,
I read your blog about led's and grow tents temps. I have a 39x39x79 AgroMax tent with  a 120watt Tri-BandLED. When I first set it up I was getting temps in the mid to upper 80's with very high humidity. I was afraid it would be too much for my plants so I turned on the 6" inline fan filter combo and it reduced it some but I didn't want to run it all of the time. I also have a smaller fan which is on a timer with the led and the inline fan. After that I turned down the intensity to the led and have turned off the inline fan and am now getting temps in the low 80's with about the same humidity. I also have the timer set for 18/6. What do you think? Should I go to full intensity at 24/7 or should I stay where I'm at? I don't want to damage the plants with high temps and humidity. This is my first indoor growing attempt any and all help would greatly be appreciated.

Hello again,
Thanks for the E-mail, glad to hear you are reading old posts. 
Most plants do well in the 80's.  Lower is better than high 80's but not by much.  You need to worry about heat stressing your plants when you get in the 90's and you will have problems with most plants above 100F.  Make sure you take the reading at the top of the plants, LED's do not give off as much heat as an HID, but that will still be your maximum temperatures. The humidity is most likely not going to be a problem for your plants however; you may have problems with mold if you have high humidity.  Ventilation can help with this.  A lot of people have problems with fungus when their plants start to flower or fruit develops so if you can get it down to 50% now, you will have fewer problems later.

You did not mention what medium you use, but watering the plants less can also lower humidity.  Plants need to take water from the soil and push it into the air (called transpiration) but if the medium is also evaporating water you will have higher humidity.  If you are using soil, make sure the top dries out before you water again.  You may need to experiment to find the best medium moisture for your plants with the lowest humidity.

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


E-mail Best Way to Improve Flowering in Plants?

Hey Doc,

  What is the best way to improve flowering in plants?

Well the first thing you want to consider is genetics.  You should look for (or try to breed for) plants that have the type of flowers you want.  You can only improve growing so much with the environment; the other 50% is genetics.  Red and yellow light tends to promote and enhance flowering in most plants.  This is why HPS and LED are so often used for flowering.  Also, you want to improve the amount of phosphorus you are giving your plants during flowering.  Nitrogen promotes vegetative growth so you want to limit how much you give plants.  HOWEVER, nitrogen is used to make DNA, and proteins in plants, so I do not recommend not giving your plants any nitrogen, just use a fertilizer that has a lower ratio of nitrogen to phosphorus and potassium.  You also want to keep temperatures and humidity at optimal levels for your plant from start to finish.  The less stress your plants have, the better they will grow.
Good Growing,
Dr. E.R. Myers


E-mail - Out Gassing and Grow Tents

What can you tell me about out gassing? I've read a lot of comments about outgassing killing off plants that were raised in the AgroMax tents that ya'll sell. can you explain/

On Sun, Jun 16, 2013 at 4:59 PM, <askthedoctor@htgsupply.com> wrote:
  Just following up, can you give me more detail, or links to sites  that talk about this out gassing?  I have not heard of this.  I would be more than happy to help if you send me some more info. 

I saw a post online where I was researching info on Grow Tents. Several people had posted about their plants dying which they thought was caused by the material that the Grow Tents were made of. I even emailed one of the company's that they had named (HTGSupply.com) to ask what they could tell me about "offgassing". They said that they had only heard of one Company that had this problem and it was "HydroHut". They also mentioned that this was several years ago and since then from what they knew; HydroHut had changed their material for their tents and had no further problems. They also informed me that when they spoke with clients who had complained about their product "offgassing" they came to the conclusion that they were keeping the temperatures extremely high(100 +) in their tents, therefore causing their plants to turn yellow and die. They assured me that their tents are safe and that if used properly with the correct temperature and ventilation there would be no problems with whatever plants I would want to grow.
Thanks again,

 I usually E-mail Perry at Sales@HTGSupply.com with equipment questions.  He said about 6-7 years ago, one company, started offering grow tents very similar to ones HTGSupply.com had at the time.  These tents were white lined tents, not the silver that is now most common.  Apparently the white poly they used reacted to light, and would emit a toxic gas that apparently kills plants.  So, many people thought this meant that EVERY grow tent made did this, regardless of who made it.
Now HTGSupply.com has the Silver lined tents. This is literally a layer of aluminum over the poly backing.  They have tested the tents.  Basically they set the tent up, with a 1000w light in it and ran it 24/7 for a week of two.  They have not been able to get those tents to off-gas at all! 
Now HTGSupply.com does still get off gas complaints.  They send out at least 50 tents per week.  Per month though we get 1 maybe 2 people claiming the tent the got is out gassing because their plants are dead or dying.  When asked how hot is it in your tent, some people say "I don't know but pretty hot" , or "I do not have a thermostat in it but real hot", or, "I do not have any ventilation in my tent and the thermostat is reading over 100 degrees F”.  If you do not have a thermometer, you need to get one asap, growing in a small space or grow tent without a thermometer, or ventilation is not good growing.
So, it seems this is an old problem that comes up now and again, but HTGSupply.com does not sell the white lined grow tents, and has done testing on the tents they do use.
Thanks for your E-mails’ I hope this was informative,
Good Growing
Dr. E.R. Myers


Growing Indoors for Maximum Health

Fiber is an important part of a healthy diet.  Fiber is cellulose (the cell wall that surrounds all plant cells).  It cannot be gotten from any animal products like meat, cheese or dairy. Fiber acts to clean out the colon which means less intestinal problems, and a lower risk of colon cancer.  Fiber from fruits and vegetables can lower blood cholesterol too.  I have seen people use powdered bran or other grainy substance to supplement their fiber intake.  Some forms of bran contain a substance that inhibits the uptake of iron in humans.  Vegetarians need to make sure they get enough iron, since it is readily found in meat, meat eaters do not often have to worry about iron intake.  Diets high in meat have been linked with gout, obesity, high cholesterol et cetera.   High iron intake in men has been linked with prostate cancer, so as with plants you do not want too much or too little of any nutrient.

Some plants that have high fiber are, beans and peas, carrots, potatoes, spinach, corn oats, wheat and fruit.
Spinach is very easy to grow indoors.  I have a friend who grows carrots for his children under an LED.  The kids like the carrots, especially since he grows them in a translucent container and the kids can watch the carrot tap root develop a little more each day.  Many varieties of bush beans could also be grown indoors.  potato's are another indoor option for someone looking for healthy foods to grow.
If anyone grows other crops indoors that are high in fiber, let me know and I will be happy to add the plants to the list above, it is not all inclusive by any means.

Good growing
Dr. E.R. Myers


E-mail - What To Do if Plants Partially Eaten

I got an E-mail from someone asking what to do: they had their plants eaten by something.  Since the plants were about an inch tall with 1-2 leaves left, I would say it is deer or more likely rabbits.  Deer tend to leave about a foot of most plants they eat.

The first thing you need to do is put a fence around the plants.  I have not known many people to have long term success with things like coyote pee or other sprays.  The problem is every time it rains they get diluted.  Feel free to try things like hot pepper spray from HTGSuply.com, but you will have to spray your plants every few days and after every rain.  If you have a few plants you can put stakes around all of them using chicken wire.  If you have an area that is less than 3-4 feet in diameter, I have found that deer will not jump into that. 
As for the plant, you want to baby the plants as much as possible, water them daily, and give them a fertilizer that is high in nitrogen.  I like Buddha grow myself. Nitrogen promotes plant growth.  Do not over do it!  Some people get the idea more is better, as I have stated previously, you want the best or optimal amount, too much nitrogen will lead to spindly weak plants that are susceptible to disease and will flower poorly or at all.

If your plants flower in mid-late summer, as soon as your plants start growing again, you will want to make sure the plants get phosphorus to promote flowering.  If you are growing a spring flowering plant, you might not get flowers until fall when the days shorten.  No matter what, you won’t get as large a yield as you would have if your plants had not been eaten, but you will get something for your troubles.

Good growing,
Dr. E.R. Myers


SOIL GNATS – Revisited –

 I have gotten a few E-mail’s about a pest called a soil gnat or fungus gnat.   I too have had to deal with these pests over the years.  Whenever I buy cheap soil at a store, which I have done now and again, I end up with soil gnats.  This is especially true if the soil’s are stored outside, where wild soil gnats can get in and start their life cycle.   I first recommended watering from the bottom, so that the top of the soil is almost always dry (this is a way to reduce soil gnats, but might not give you the best growth rate - read post on soil moisture).   Unfortunately, what I have noticed is that the soil gnats, which need moist soil to reproduce, simply go and get to their food/nesting areas through the small drain holes in the bottom of the pots. 

If you have noticed this too, one new thing you may want to try is the felt cloth pots.  I have and continue to use these cloth pots.  The idea is the gnats cannot get through the cloth at the bottom.  One warning,  I have noticed the cloth pots, since they are cloth can be flimsy.  I use the ½, 1 and 2 gallon sizes.  I have used the three gallon size, but it would not hold its shape too well  so that whenever I watered it, some water would drip out THROUGH the felt cloth over the tray below.   I ended up transplanting the banana tree in the 3 gallon cloth pot into a larger hard plastic pot.   I recommend trying some non-chemical solutions to dealing with soil gnats, I have listed chemical waysto treat soil gnats in my previous post.
Good Growing,
Dr. E.R. Myers


The Right Depth for Planting Seeds

Depending on where you live, you may already have your plants in the ground, but it not too late to start a few more seeds for your outdoor garden, and there are 365 days of good weather for we indoor growers.
If you are growing something like corn or beans that have a larger seed, you will want to put it 1\4 to \2 of an inch below the soil.  Always read the directions, I am surprised how many people fail to just read the directions on the seeds they by.  You want to be consistent with all your seeds (see my post on scientific tests).  To help with consistency you could use a pen or most anything that is stick like to put holes in your grow medium (I am using a mostly soil with some perlite/vermiculite mixed in here). Click here to see my test for the best medium for seed germination

Simply measure the distance on the pen, wrap some tape around the pen at that distance and you have a handy tool to make consistent holes so that all your seeds will start off at the optimal spot.

Good Growing,
Dr. E.R. Myers


E-mail - Flying Insects in Growroom

  I have little fruit flies in my garden.  I am using a soil mixture in 3 gallon pots.  I read on your blog about putting sand on top of the soil and I tried putting sand on top of my pots, but it has not gotten rid of them.  I am going to eat my plants so I don’t want to use any chemicals.  What can I do to get rid of these little bugs?

Thanks for the E-mail.  I think you have what I call soil gnats or fungus gnats.  The adults are harmless; they don’t sting or bite you or your plants.  The larvae (like when a caterpillar turns into a butterfly) eat organic matter in the soil and can eat root hairs which would harm the plants and slow growth.  A test to see if your soil is infested with soil gnat larvae is to look very closely (use a magnifying lens if you have one) you will see tiny little white ‘worms’ or larvae.  Another test is to put a piece of raw potato on top of your soil.  In  just one day you should see little black headed larvae under or even on the potato chowing down.  Since you put sand on top of the soil (perlite or any substance free of organic matter and that dries out will work) you might not be able to do this.  The adults live a week or so, so you will still see them flying for that long.  If it has been over a week, or you see MORE adults you still have a problem.  What might happen is that the soil gnats could be laying eggs using the drainage holes.  Pick up the pots.  You should notice some soil gnats flying from ON the plant, but what you want to look for is soil gnats UNDER the pots.  If you see a bunch of gnats under your pots, this is why putting sand on top did not work, they just found another place to lay their eggs in your grow area.  
You should clean out your trays of any plant matter.  You can then fill the trays ½ full with a 1-4 ratio of hydrogen peroxide to water.  One part 3% hydrogen peroxide, and four parts tap water.  This will work better if the plant/soil is dry.  Make sure the mixture covers the drainage holes for a few minutes.  The mixture should kill most of the larvae but won’t harm your plants if you make the 1-4 ratio correctly and only let the plants sit in the solution a few minutes.

Last, you should get some yellow stickytraps from HTGSupply.com to monitor the soil gnat population.  If you could harvest all your plants at once and clean up everything with the hydrogen peroxide (or bleach for the pots and trays) you should try to wait a week to make sure all the adults in your house are dead.  If you have house plants, you may want to treat them with an insecticide otherwise soil gnats in your house plants will find their way to your indoor garden again.
Let me know if this works
Good Growing,
Dr. E.R. Myers

Click here for other options including insecticides to deal with indoor pests.