Ripe, homegrown tomatoes are full flavored, juicy, and the pride of gardeners. At the end of the growing season, you may have an abundant tomato crop of green and reddish tomatoes on your plant that will not have an opportunity to fully ripen on the vine. Or, in the heat of summer when temperatures reach above 85 degrees Fahrenheit for several days, the ripening of your tomatoes may stall. Green tomatoes can be forced to ripen with some success, but ripening reddish tomatoes will yield almost complete success.
Pick tomatoes with a tinge of red from your plants.
Trim the stems to less than 1/2 inch on the harvested reddish tomatoes. Longer stems may puncture neighboring tomatoes during the ripening process, and tomatoes that have the stem pulled off are susceptible to decay.
Place the reddish tomatoes in the bottom of a clean, dry cardboard box. Cover the layer of tomatoes with several sheets of newspaper. The newspaper will hold in the ethylene gas the tomatoes naturally release. Ethylene gas is an important element of the ripening process. As an alternative, you can place the tomatoes into a paper bag to ripen.
Set the box or bag in a warm, dry location, out of direct sun. Check the tomatoes every day or so, removing the tomatoes that have ripened.