The reason most home gardeners grow tomatoes is for vine-ripened flavor. At the end of the growing season, leaving fruit on the vine is only possible for so long. When a light frost threatens, covering the vine is an option. This technique relies on heat radiated by warm soil to be trapped by the cover overnight until warmer weather arrives the following day. If the forecast is for a severe freeze or a frost is followed by several days of cold weather and additional frosty nights, harvest before the frost event and ripen the tomatoes indoors.
Pick fruit that has turned color, even partially. Green fruit that has reached a glossy-green and is at least three-fourths of normal size also can be picked. Remove the stems, wash the tomatoes in water and allow them to air dry on absorbent paper towels. Save only blemish-free fruit for ripening indoors – fruit with soft spots, sunscald or holes from tomato fruit worm should not be included with others for ripening.
Low humidity causes fruit to shrivel while high humidity causes mold. Some gardeners place fruit one or two layers deep in cardboard boxes in a room out of the direct sun, while other gardeners prefer to keep tomatoes from shriveling by wrapping each fruit in newspaper or waxed paper. Storing several fruits in plastic bags retains even more humidity in very dry situations. Hanging whole plants with fruit still attached, a practice many learned in the humid East, is not as effective here in the dry West. Every few days monitor all fruit stored for ripening and remove fruit that has started to spoil before rot moves to adjacent fruit.
The ripest fruit in a group produces ethylene gas, a natural ripening hormone that will ripen adjacent green fruit in storage. You can speed ripening by placing ripe fruit with green, and retard ripening by removing ripe from green fruit.
Green fruit ripens in about two weeks at 65 to 70 degrees F. A storage life of three to four weeks can be expected at 55 degree F temperatures. Because storage below 50 degrees produces bland, off-flavor tomatoes, don’t store tomatoes in the refrigerator.
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