We do have a greenhouse and a regular garden. We built the greenhouse using plastic tubing (pvc electric tubing?) and vapor barrier plastic sheeting to cover. I grew tomatoes, eggplant, peppers, celery, bok choy and cukes.
I planted typical cold weather crops in the regular garden: potatos, leeks, peas, garlic,kale, spinach and green beans. This year, I plan on brussel sprouts, cabbage, broc and cauli. in the cold weather garden as well.