I’ve always wondered about that. ‘In his diary for August 7, 1765, Washington writes, “Began to separate the Male from the Female hemp … rather too late.” Female marijuana plants are the ones that contain enough THC to be worth smoking. Some take this to mean Washington was cultivating the plant not just for fiber. Of course, two days later Washington says he put the hemp in the river to soak and separate out the fibers, and later in September that he started to harvest the seed. That suggests he divided the plants because the males made stronger fiber while the female plants produced the seed needed for the next year’s crop. Jefferson in his Farm Book wrote that a female plant would produce a quart of seed, and a bushel of seed was enough to plant an acre.’ - http://www.straightdope.com/columns/read/2912/did-george-washington-and-thomas-jefferson-grow-marijuana
Interesting.
I think the urban legend we got was that Washington actually wrote that he preferred smoking hemp over tobacco.
I don’t think that is written anywhere in his papers.