My friend uses netting. In his area his plants are the only green thing from mid summer on. His plants are assaulted by everything. The rats or squirrels will eat a ring of the green from around the bottom of the stem and the entire plant just dies. He has deer, squirrels, rats and birds attacking his grow.

He is very thorough with the netting and it works pretty well. You just have to make sure it gets to the ground and there are no openings. He has a sort of corral of sticks natural plants around the plants he is growing that help keep the net in place.