Tomatoes Will Not Ripen

How Tomatoes Ripen

• Tomatoes ripen well in a climate of plenty of sunshine, spring showers and moderate summer temperatures. Tomatoes won't ripen if temperatures get too hot -- the most common cause of stubbornly green tomatoes. The plant's leaves provide the hormones and nutrients that make tomatoes red. Full ripening takes 40 to 60 days after fertilization. Halfway through this time period, a tomato reaches its full size and begins to turn from green to red.

Temperature

• If air temperature rises about 85 Fahrenheit, tomato plants cannot produce the carotene and lycopene essential for ripe, red fruit. Roots need to be below 80 F. If your region has temperatures above 85 F, shade your tomato plants to reduce temperature. Add mulch around the roots of the plants to protect roots from high heat. Cold temperatures, on the other hand, slow ripening in tomatoes that are not far enough along in the ripening process. As temperatures grow cooler, red tomatoes will continue to ripen, but chill can damage the ripening process in tomatoes that are still green.

What to Do

• Ripening a big load of tomatoes requires sufficient leaf space. Growth demands can overload a plant so it has difficulty balancing growth with the components required for ripe, delicious fruit. Remove excess green tomatoes from a plant to ease the load and hasten ripening. If there are just a few weeks left before frost, remove extra blossoms to encourage remaining fruit to ripen vigorously. Protect the plants and control temperature by adding mulch and boosting moisture levels. Adding extra fertilizer is not likely to help ripen tomatoes, as the problem is not related to nutritional deficiency.

Harvesting Green Tomatoes

• Pulling off those extra green tomatoes shouldn't be considered a loss, as they can be used in delicious recipes and some may be ripened off the vine. Ripen "mature" green tomatoes off the vine for good flavor. These tomatoes can be identified by the following signs: full size, skin turning from green to white, seeds encased in gel and no empty space within the fruit. Ripen in a cardboard box at room temperature and wait a few weeks, monitoring for spoilage. Alternately, you can fry green tomatoes, make them into relish or stew them.