ABSTRACT
Plant spacing is determined by the size of the mature plant. You must consider the actual floor area as the basis for your plant spacing. For example, if you have a small hydroponic unit of dimensions 2 feet by 4 feet that gives you a total area of 8 square feet. Tomatoes require 3.5 to 4 square feet per plant, but that is floor area. You may think that you can only locate two tomato plants in the hydroponic unit, but not so. The roots of most plants can be contained in fairly small areas as long as they receive adequate oxygen, water, and nutrients. In reality you could grow up to eight tomato plants in those 8 square feet of the hydroponic system. But you must train the plants outward in a V-cordon method so that at the top of the support cables the total floor area occupied by those eight plants under your lights would be equivalent to 28 to 32 square feet. That would give the plants adequate spacing so that light could enter the canopy and you would have sufficient access for training the plants.
