the low-maintenance winter crop that improves your soil

My summer garden is starting to wind down. We had a couple nights this past week where the lows dipped dangerously close to freezing, but I covered my plants on those evenings and all the tomatoes, cucumbers, and zucchini were spared! The rest of the garden was left to fend for itself, but I'm not too sad about it—it's time for those plants to come out and for new ones to go in. I have a healthy fall garden already planted (that will overwinter nicely, thanks to my timing based on Persephone...