View from Rooftop or......... how big is your garden?
My 9 raised beds total about 235 sq ft. Plus I have the borders with fruit trees, the chicken coop (providing eggs) and other edibles. But in order to be completely sustainable, eating a vegan diet, I would need about 4,000 sq ft (using sustainable biointensive practices) to feed one person. In comparison, the average U.S. diet requires 30,000 sq ft of land to feed one person. Those eating high meat diets use up to 60,000 sq ft (using conventional farming practices).
So yes, I still go to the farmers market every week and belong to a CSA. But I know I will never starve, having what I have available at home.
I encourage everyone to try and grow something to eat!