I do the same here in central Oklahoma. My weed room, plastic covered old house back porch, also has a small electric heater I keep at 40*F. Even in the dead of winter if the sun is shining it can get 60*F or more. Night temps do drop and the heater takes over. I think I do have some cold spots within the room and try to keep the less tolerant of plants away from these. Okie zone 7a aka " Ranchmama " ***************************** ----- Original Message ----- From: "George Shirley" <gshirley@laol.net> > I've got a small electric heater, thermostatically controlled and I experimented with it to find the best setting to maintain 40F. Can't speak for how it would work in a really cold climate but works well here in SW Louisiana. > > George