A few years ago I talked with Brian Murphy of QDMA about this and he said if you have a heavy deer population like is common in the southeast that a 8 or 10 acre plot would be the smallest he would mess with. Sounded like a lot to me, but I would plant all I could. If you could fence it with some of the deer ribbon fencing I have seen till the beans get 8 or 10 inches high smaller acerage would be more helpful.