Hey Harold, I'm growing my 3rd season now and things are going great. Polycarb on most of the dome now, and I have a thermostat kerosene heater to supplement the greenhouse effect. I'm still not 365 though, because even if you can keep the plants from freezing things like tomatoes don't grow very fast if it gets cold at night. Spinach and such no sweat. Beds should really be built off of the ground and the ground insulated. The next thing I really need to make is a misting system, because even with all of the fans running like crazy it is still too hot in there at times. evaportive cooling is key, and keeps the humidity up as well. I'm in Colorado.