Finally, hemp would serve as an ideal weed barrier for organic farming. This close spacing prevents branching, which means the plants grow a straight stem about the size of a finger, with only a small canopy of leaves at the top. To maximize fiber quality, the plants are harvested when the male plants begin to pollinate All this means that industrial hemp is unsuitable as a cover crop for marijuana. Marijuana is planted with wide spacing to encourage branching. The narrow spacing of industrial hemp means it is impossible to enter a field without leaving a noticeable trail.
Industrial hemp is cut before flowering, while marijuana is harvested for the flowers.
Any marijuana plants growing in the hemp field would be cut before they were worth anything. Male plants are eliminated for marijuana cultivation, so pollen from male hemp plants would destroy any nearby marijuana crop. As most police agencies will tell you, corn is the preferred cover crop. It has been estimated that hemp could be used to produce 25-50,000 products. Hemp fiber is one of the strongest natural fibers on earth.