would be caure full cause on 1/2 an acre you could get some serious plantation going but it's not worth the risk, i say stick to 10 if its for personal use cause if you grow sativas you might get 200/300 grams per plant or more. sure ly you wont beable to smoke all 10 with in a year?
remember be safe, DONT TELL ANY ONE YOU GROW, and pay in cash