Ripen green tomatoes indoors by discarding the rotten tomatoes, and then washing and placing the good tomatoes into a shallow cardboard box. Leave room between the tomatoes, place the box in an insulated garage, and let the tomatoes ripen over several weeks.Continue Reading
Pick the green tomatoes before the first frost. Examine the tomatoes for bruises and soft spots, then discard the rotten tomatoes. Wash the remaining tomatoes under cool running water, and dry them thoroughly with a hand towel.
Choose a shallow cardboard box that is made of thick material. Line the box with several layers of newspapers or paper towels to ensure that any moisture from the tomatoes is soaked up upon contact.
Place the tomatoes one at a time in the cardboard box about 2 inches apart, making sure that they do not touch each other. Add only enough tomatoes to make one layer. Use another cardboard box if you have more tomatoes.
Carefully place the cardboard box in a garage or dehumidified basement away from direct light and in a cool, dry area. Allow the tomatoes to ripen over the course of a few weeks up to 3 months. Check them periodically to remove rotten tomatoes.