Thank you, Phly. I just found out that our current fence posts are two feet into the ground and that fence was installed three-four years ago and it still holds up good-it's just not high enough. I guess i'll go with 2 ft deep, thank you so much i've been worrying about this for days!
PaintHorseMares, I will make sure he has enough hay but I just don't feel right about having such a low fence-I'd be heartbroken if he jumped out again and got injured by a car or caused a fatal accident.