Only because I don't have a place all to myself to do so.
Possession of less than 10g will get you a $100 fine where I live. Growing it, though? Pretty sure that's still a felony in Maryland, USA, but it could be a misdemeanor. I honestly would like to move to one of the legal states and legitimately try my hand at growing. Only thing holding me back is the size of my bank account and the fact that I've invested more years than I'd like to throw away at a job that I haven't found a way to be able to transfer from one state to another.
[EDIT: Just looked it up. State law on growing weed is that a person caught will either be charged with simple possession or possession with intent to deliver, based on the amounts being grown and the penalties listed for those two charges. So if you're growing less than 10g, misdemeanor punishable by up to a year in jail and a $1,000 fine, but if you grow a milligram over 10g then you're hit with possession with intent to deliver, punishable by up to 5 years in prison and a $15,000 fine if caught with anywhere from 10g to fucking 50lbs. Crazy. I feel like I may be interpreting that wrong, though....]