Originally posted by Barb (and Art): And that you have a good supply of water!
Yes, that's especially important! Our garden wells dried up last year, along with our pond, so we had no water for the garden from mid-July on. Needless to say, our garden didn't grow.
Even with an irrigation system, our garden got taken by surprise last summer by a very hot spell and basically got burned. Healthy plantlets of zucchinis and lettuces just got burned. If you are in the South, I would aim to grow stuff that you can harvest before the really hot weather kicks in. My garden is only really good in April when all the Spring bulbs come out - after that it just becomes a desert.