I have not tried peppers, but did start cucumbers in the spring using the winter sow method. I really got a head start on them by doing this. Seems the milk jugs kept the soil and plants warm enough until all danger of frost was past.
Things like: kale, chard, peas, collards did wonderful. Some of the squash should work. How many times have you found squash growing in the compost in the garden bed?
Snow peas, spinach, lettuces, asparagus, peas, kohlrabi, red cabbage and pak choi.
