This is really about Foraging for PART of your food needs, rather than formal gardening/farming.
I think in contains some sound advice on both WHICH FOODS to concentrate your foraging skills upon and WHY.
http://survivalskills.guide/gathering-wild-foods-subsistence/Even if there are no other people/animals trying to survive in the same area, you may not find a garden-of-eden type of resource.
Hence, preps should include at least a minimum amount of seed stock AND you should be looking for seeds as you forage.
You may have to survive on what you have in stores plus whatever you forage, while at the same time, you will be planting for later harvest.
This is why a full years worth of food stock is recommended.
You can expect to get hungry and lose weight...