We just moved to a place with a greenhouse with raised beds. I would like to grow all the fixin's for salad, i.e. lettuce, tomatoes, onions, anything else that's tasty and do this year-round. Is this possible? I obviously don't know much about gardening. We live in North Central Idaho where there are two seasons...winter and August! But seriously, we are at about 1750 feet and the winters get into the teens at times. Would this be possible without heat since the beds are raised? Any suggestions, ideas, abusive remarks?