Setting up a closet grow space -1

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

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 - Sea of Green

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....

Click here to read a post comparing SCROG to a traditional grow method

Good Growing
Dr. E.R. Myers


E-mail - The Standards Questions about LED's

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.


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