I bought my greenhouse because I grow a lot of tropical Zone 9 and 10 plants that will not survive my Zone 8 Winters and have to be overwintered in a non freezing place. I heat my greenhouse only to "don't freeze" temperatures. It also gives me a jump start on Spring by allowing me to start seeds 2 months earlier - on a sunny day the temperature can be in the low to mid 60's outside, but inside the closed greenhouse it can get into the upper 80's to mid 90's. By the time it's safe to plant things in the ground, all the annual I started from seeds in late January are within weeks of blooming instead of months and everything else is actively growing.
