Goings Ons

I moved these mandevilla and bougainvillea into the greenhouse last week because there was supposed to be a freeze.  I was under the impression that a greenhouse would protect plants from freezes.  Apparently, that is not the case.  The plants are now completely dead.  Somewhere I read that I should put a barrel of water in the greenhouse.  Theoretically, the water would heat up during the day and then the heat would dissipate during the night and help, at least a little, to keep some warmth in the greenhouse.  Also, not true.  The water in the barrel remains cold at all times.

I wanted to grow some veggies in the greenhouse this winter...maybe some lettuce or tomatoes.  So, the question is, what is the trade off in cost?  Is it cheaper just to buy lettuce and tomatoes at the grocery store or to heat the greenhouse during the night with heat lamps or a space heater?

This is our new propane tank.  Think it's big enough?  After we get it taken off of the trailer, Tom is going to hook it up to a generator so that if we lose power, the propane will run the generator, which will power the house.