Found a really good article on www.motherearthnews.com
“Right now, before you forget, put a rubber band around your wrist to remind you of one gardening task that cannot be postponed: Planting seeds for fall garden vegetables. As summer draws to a close, gardens everywhere can morph into a tapestry of delicious greens, from tender lettuce to frost-proof spinach, with a sprinkling of red mustard added for spice. In North America’s southern half, as long as seeds germinate in late July or early August, fall gardens can grow the best cabbage, broccoli, and cauliflower you’ve ever tasted. In colder climates it’s prime time to sow carrots, rutabagas, and turnips to harvest in the fall. Filling space vacated by spring crops with summer-sown vegetables will keep your garden productive well into fall, and even winter.
Granted, the height of summer is not the best time to start tender seedlings of anything. Hot days, sparse rain, and heavy pest pressure must be factored into a sound planting plan, and then there’s the challenge of keeping fall plantings on schedule. But you can meet all of the basic requirements for a successful, surprisingly low-maintenance fall garden by following the steps outlined below. The time you invest now will pay off big time as you continue to harvest fresh veggies from your garden long after frost has killed your tomatoes and blackened your beans.”