This is my first year with a hoop house. I live in north Texas (Zone 7b). I have a few tropical hibiscus and what not in big pots that I don't want to bring in. I keep a lidless crockpot full of water going, which makes the air nice and moist. I have a heat lamp and a rigged waterbed heater for bottom heat. I just hate to chance it and find out out my hoophouse wasn't warm enough. Thanks so much!