Hemp, a sister plant of Marijuana contains such a low level of THC (the psychoactive chemical in marijuana that produces the euphoric feeling) that it is impossible to get 'high' from any form of ingestion. Furthermore, Hemp is the MOST annualy renewable industrial crop.
4 times more productive as wood (per acre), and 2 times more productive as cotton (per acre) Hemp requires no pesticides! (50% of the world's pesticide use is used on cotton)
Furthermore, 50% hemp clothing reflects UV rays up to 30% better, is more water absorbant and mold resistant.
Lastly, making particle boards, wood studs and pressed boards of Hemp (due to it's longer stands) will produce lighter AND stronger materials.