How To Ripen Green Tomatoes Off the Vine

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Last Updated: 
November 1, 2007

CORVALLIS, Ore. – As autumn progresses, many green tomatoes will be left on the tomato plant vines, but don't despair. You can ripen “mature green” tomatoes by picking them and storing them off the vine.

To test whether green tomatoes are mature enough to ripen off the vine, cut one in half with a knife. If the interior is yellowish and the tissues are jelly-like or sticky, it will probably ripen, says Ross Penhallegon, Oregon State University Extension horticulturist. Mature green tomatoes may also have a pink or reddish tinge on the blossom end.

Tomatoes that are not yet to this mature green stage won't ripen off the vine. Immature green tomatoes have soft seeds that are easily cut through. The pulp is not yet jelly-like. Unripe tomatoes can be used for canning or fresh cooking.

Place mature green tomatoes in thick straw or in shallow box in a room, shed or garage, where the temperature ranges from 55 to 70 degrees. They will ripen over a period of three to four weeks. Place newspaper between rows of tomatoes, or wrap them individually to prevent decay from spreading from fruit to fruit if you are storing them in boxes. Sunlight is not needed to ripen tomatoes; they ripen best in the dark.

Tomatoes may suffer from chilling injury at temperatures below 50 degrees if held there for longer than two weeks, or at 41 degrees for longer than 6-8 days. Chilling injury may prevent your green, mature tomatoes from ripening and keep them from developing their full color and flavor. It may also cause them to spoil more rapidly. Remember to store only tomatoes that have not been exposed to frost. Cold damage, including frost and cooler temperatures, is cumulative and may have happened prior to harvest, out in the garden.

Check your stored tomatoes every few days for signs of decay. Dispose of damaged fruit immediately, as rot can spread rapidly in storage.

Author: Carol Savonen
Source: Ross Penhallegon