When it comes to food stockpiling (assuming a long-term scenerio before services are restored, if ever), I try to keep a couple of things in mind:
1. You've got to have something to eat while you're gardening and during the off season.
2. You've got to have ways to preserve your food for the next year. For meats, drying, smoking, and pressure canning. For fruits, drying and canning with both sugars and acids. For vegetables, drying, pickling, and pressure canning. These are some of the most common practices.
The stockpile then needs to reflect deficiencies in the above. With respect to point 1, what is not being represented in your garden? Are you only growing fruits and vegetables? Those are awesome for vitamins and general nutrition, but what about grains (wheat, dent/pop corn, rice, etc.) or beans (pinto, red, blackeye, etc.)? How will you get plenty of carbs to keep working? With respect to point 2, do you have supplies to store your harvest? Containers (plastic and glass), salt, vinegar, sugar, etc. will be needed for storage.
So, a stockpile of things that are relatively cheap and readily attainable at the moment is something everyone should consider. If packed properly with mylar and O2 absorbers, almost all of this stuff will last 20+ years (much longer than canned goods and MRE's), allowing for rotation schedules based on the longer time scale. How many of us are practicing growing enough rice or wheat for a family or making our own vinegar or sugar (honey included)? It's harder than it looks. I'd rather spend a little now on the things I eat, that will store for a long time, than be without (even for a short-term scenerio). We often take much of these things for granted. Start small and build.