The question in issue #41 was:
What is the greatest number of plants you ever grew per square foot? How did you do it? In what medium? How many watts per square foot? What was your yield?
Here are some of the answers I received:
I grew nine plants per square foot under a 1000w HPS. The growing area was six by six feet, or 36 square feet. That’s approximately 28 watts per square foot. I used plastic soda bottles with the tops cut off. Nine of them fit in a square foot. I cut six triangular holes in each bottle at the lower and mid levels. I filled the bottles with a combination of Black Gold Organic Potting Mix to which I added bone meal, rock phosphate, greensand, and crushed lava rock. I supplemented this with Ancient Organics Primal Harvest bloom fertilizer made primarily from seabird guano (0-12-1).
I used a tube and tray system called Conetainer Super Cells, to make the clones. It is a 12″ x 24″ tray that suspends 98 plastic tubes that are 1.5″ diameter at top, 8.25″ length and has a 10 cubic inch capacity. I recommend using these as they save time and space if you need to produce a lot of clones. You can set the unit in a tray of water for capillary uptake for a few days. A complete unit costs about $35. I kept the light on continuously while the plantlets were in the rooting containers.
When the clones were five to six inches I transplanted them into the soda bottles and immediately changed the lighting regimen to 12/12. The plants topped out at 18″. Many of the buds were 12″ long with a minimum diameter of 1.5″. I was growing a purple Indica variety and grew one single stem and no branches. I averaged a quarter ounce per plant and harvested just over two pounds seven weeks from flower forcing. The endeavor was labor intensive but well worth it. The method won’t work with most varieties. It takes a certain kind of strain and I had to experiment with clones of different strains for months before I found just the right one for this technique.
I grew 2.5 plants per square foot using a homemade hydroponics system. I used horticultural clay pebbles in five-inch net pots using 95 watts of water-cooled HPS lamps. The garden was 10 square feet and produced 2500 grams every 45 days.
I have seen many successful gardens with tight planting.
One garden held eight plants per 10 x 20 inch tray. Three trays with 24 plants occupied four square feet. The plants were grown in four-inch rockwool cubes.
It isn’t unusual to see plants packed four per square foot. The plants can be grown in individual five-inch square containers. These maximize space for the roots. It’s also easy to place rooted cubes along cocoamat or rockwool slabs.
New Expert Question:
What is the biggest plant that you have grown outdoors or indoors? How did you do it? Were any special treatments or techniques used? No fish stories. A photo will be required.
Send your story and photo to Ask Ed, postmarked before June 28. All featured answers will receive a copy of the fabulous Big Book of Buds from Quick Trading. Plus one randomly selected correct answer will receive a set of three 5-gallon bags to make fine bubblehash, generously donated by Fresh Headies.
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