My tiny garden in Houston did a pretty good job this fall of growing nutritious food. Two of the most vitamin-packed crops one can grow are sweet potatoes and collards, and my two little raised beds grew both, well.
The sweet potatoes are Garnets. I planted a whole potato in one of the beds last spring, and it sprouted little plants, which I moved to 12" spacings. They grew there all summer, completely unattended by me, through a long drought and very hot temperatures. I dug them right before an unusual frost, in early December. Some winters, the temperature in Houston never goes below freezing, but this time, it not only got cold; it also snowed! You can see the snow on the collard greens here.
I planted the collard greens in October; they don't do well in hot weather, so I waited until it cooled off some. At first they had a few problems with bugs, but as the weather cooled, the bugs went away. They love frost; it makes them sweeter.