E-mail -- Looking to Increase Yields.

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.

Read my latest post comparing SCROG to a traditional grow method



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?
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

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

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