You can plant any veggies you like that prefer cool temperatures: lettuce, spinach, radishes, broccoli, cauliflower, kale, cabbage, peas or greens. The best rule of thumb is to find your first frost date and plant 60 days before that date. Most of these crops grow quickly and can be harvested before the weather gets nasty. If you don't have a frost in your region, plant at any time. As long as the temps stay above freezing the crops I listed above will be fine."