The pH of Some Commonly Grown Plants Using Hydroponics

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.  See my post on checking soil/soiless medium pH

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

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

I have published 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 jalapeƱo 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

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

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.

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