Most gardeners get pretty excited about the first home-grown tomatoes of the year. A lot of people also find it difficult to be entirely rational about the last. Tomatoes are not just the soul of a salad, they're the sand between our toes, the fireflies on soft summer nights -- the quintessence of warm ripeness. No wonder, when the nights grow cool, that gardeners scramble to save their tomatoes.
Even in the summer, it takes several weeks from the time a tomato sets fruit until it ripens. In fall, tomatoes simply run out of time. But there are ways to cheat the calendar:
Some gardeners pick the leaves off tomato plants to expose the fruit to the season's last rays of sunshine. It's better to prune new stems back, and let the existing leaves remain: leaves are supplying nutrients to the ripening fruit.
Try thinning some fruit from plants loaded with tomatoes. Tomato plants need energy to produce their crop, and it takes longer for the tomatoes to ripen on a plant heavy with fruit.
In cool fall weather, covering tomato plants with a sheet may help ripening tomatoes turn red, but green tomatoes simply will not ripen once temperatures drop to 50 degrees. Nearly ripe tomatoes tolerate cool temperatures better than green tomatoes.
Pick mature green tomatoes, very light green or almost white, and let them ripen indoors. These tomatoes may not pull easily from the vines; cut them off with a short stem attached. If you're not sure whether the tomatoes you picked will ripen, cut one in half: the seeds of mature green tomatoes are surrounded by gel. If the knife cuts some of the seeds in half, the tomato is not mature enough to ripen.
Some gardeners pull whole tomato plants up and hang them in a frost-free place so the fruit can ripen on the vine. Ripening tomatoes (on or off the vine) should be stored at temperatures between 55 degrees and 70 degrees. Cooler temperatures will slow things down; it takes about two weeks for tomatoes to ripen at 70 degrees, and twice as long when the temperature is only in the mid 50s.