Construct a frame around your plants and cover it with clear plastic to form a minigreenhouse and give your tomatoes as much as two weeks additional growing time. If sunlight reaches the soil around the plants, you can also gain some warmth by covering the soil with black plastic. Be sure to brace things so they will not be blown away by wind. If you simply cover your plants at night, not much will be gained in providing warmth for them, and if you neglect removing the cover early in the morning, you will be depriving the plants from some valuable sunlight.
As we move into the fall all of our efforts to extend the growing season produce diminishing returns. Cooler temperatures and fewer hours of sunlight take their toll; however, there are some things to do to help your crop continue to maturity. Cut back the growing tips of the vines and any little tomatoes that will not have a chance to ripen. This trimming will direct the plant's energy into the tomatoes that will be able to ripen. Prune off any leaves that start to yellow. Pick the tomatoes as soon as they show signs of ripening (pinkish in color) and continue their ripening indoors. Picking early also allows the plant's energy to be directed to the remaining developing tomatoes.
