Still in progress of building an 18' X 24' hoop house. I have used gallon water jugs around tomato plants for years, to keep nighttime temps up so fruit will set. I put the jug inside of a 5 gallon pail with the bottom cut out, then plant the tomato in the middle. I get earlier planting, as this contraption will protect tomatoes down to 25 degrees or so, if it gets colder than that, I will cover the container with row cover. By the time the tomatoes are above the bucket, danger of frost has passed. This will be the first year all of my tomatoes are in a greenhouse/hoophouse. I do not have heat for it, but do have raised beds and do plan to use some water storage around plants as well as row cover to extend the season. Once I get the skin on (sometime this next week, it arrived today), then I will monitor temps high and low compared to high and low outside in our mountainous zone 6.
Have already started seeds in the house, once they sprout i move them to a small attached greenhouse, and put them inside a portable greenhouse. I set the plants in trays on top of light cables,. Then have water jugs in the bottom of the portable, for heat storage. I do put a small heater in this greenhouse, to keep night time temps up until it warms enough in the spring.
