From HighGrow, Grow Guide:
My name is Jim and I have been actively growing marijuana for six years.
By actively, I mean that I have consistently attempted to grow the largest, most potent crop of marijuana possible in my small, but sunny greenhouse. In my "active attempts", I have discovered a method of doubling the volume of my harvests and I would now like to share this discovery with anyone else out there cultivating marijuana in a limited growing area.
Living in South Africa, we are fortunate to experience a warm climate with long sunny days and with these conditions, I figured that I'd have the most success growing my plants in an outdoor greenhouse. So, with privacy in mind, I built a small greenhouse in a very secluded part of my garden, and in eight large pots, I planted twenty of the best seeds I could lay my hands on.
Although my first harvest was very potent, the plants quickly filled up all the available space and started growing along the greenhouse roof. By growing in a greenhouse, my plants did not experience windy stem-strengthening conditions and when the buds started developing, some of the branches started to sag with the increased weight. I was forced to support these branches by tying them to the roof with string. At harvest time, I noticed something very interesting...
Many of the buds growing on the lower, supported branches developed better than the buds that were growing higher and along the roof. It was as if the plants now used less energy growing stem support and more energy developing buds.
With my next crop, I planted less seeds (this time a cross of my own Swazi/Skunk hybrid) and spent more time trying to keep the plants away from the roof. I did this by tying the branches down horizontally until the flowers started developing and then, as the weight increased, supporting the branches from the greenhouse roof. Wow, what a difference!! The quality was excellent, but this time I had also increased the quantity of buds per plant in the small area available.
Realising that the most potent buds develop near the tips of the plants and having discovered that the strongest growing buds developed on supported branches growing horizontally, I planned my next harvest. I had to keep the branches away from the greenhouse roof, growing horizontally, supported, with more energy available for developing buds. For me, there was only one solution...
At a local hardware store, I purchased a few square meters of a thin wire mesh commonly used for light-duty fencing. I suspended the mesh approximately two-thirds of the distance between the floor and the (two-meter high) roof, horizontally, over the growing seedlings. As the growing tips reached the mesh and started growing through the openings, I pulled them down again and trained them horizontally into all the open spaces available. I performed this pulling-training procedure every few days until the first female buds started showing.
By this time, the few plants that I had growing below the mesh had produced a tight matting of growing tips all along the surface of the wire. Sadly, few buds developed in the limited light below the mesh, but above the surface, every square centimeter was filled with strongly growing tips with plenty of room to develop thick, well supported buds. By the time the first flowering buds started turning brown (which is usually the time I prefer to harvest), the tips of the branches had almost reached the roof of my greenhouse. The volume and quality of buds above the mesh had far exceeded any of my previous attempts. Hooooray!!!
I hope this helps someone?
Looks like 30 inches off the ground won't help much. Treeman, you think 48 would be better? Also, I think I learned the answer to the placement question... looks like it would be way labor intensive to thread the tip, so I'll do it in the middle of a 5x8 rigid screen, top it at about 24" and spread the branches apart and up. Yes?