I would recomend that anyone planing on surviving on a home garden, look into the protein content of what they choose as crops. High protean is a very needed ingredient of survival. Also, you better be prepared for re planting of the next season, Hi-Bread seeds from your crops will not reproduce the same verity, they will revert to a common plant or no crop at all.
I would recomend that you look into how much you and your family eat now, and increase it by say 50%, as you will not have all the Twinkies around to subsidise your hunger.
Survival farming during SHTF times, is not very easy, and failure means starvation.
Just a thought.
Bill