AMES, Iowa – With fall officially here and temperatures cooling down, it's the perfect time to harvest remaining garden produce. What is the perfect timing for getting the rest of the season’s bounty out of gardens and properly storing it for optimal use?
ISU Extension and Outreach horticulturists can help answer questions about how to harvest and store garden produce in fall.
How do I harvest and store sweet potatoes?
Harvest sweet potatoes immediately before or after a vine killing frost. When harvesting sweet potatoes, dig carefully to avoid cutting or bruising the roots. After harvest, cure sweet potatoes for one week at a temperature of 80 to 85 degrees Fahrenheit and relative humidity of 90 to 95 percent. Curing promotes healing of minor cuts and bruises, prolonging the storage life of sweet potatoes. Curing also improves the flavor of sweet potatoes as starches are converted to sugars during the curing process.
After curing, store sweet potatoes at a temperature of 55 to 60 degrees Fahrenheit and relative humidity of 85 to 90 percent. Storage temperatures above 60 degrees Fahrenheit may stimulate sprouting. Sweet potatoes may develop an off-flavor and the flesh may become discolored when stored at temperatures below 55 degrees Fahrenheit. If properly cured and stored, sweet potatoes can be stored for four to six months.
How do I harvest and store winter squash?
Harvest winter squash when the fruit are fully mature. Mature winter squash have very hard skins that are difficult to puncture with the thumbnail. Additionally, mature winter squash have dull-looking surfaces.
When harvesting winter squash, handle them carefully to avoid cuts and bruises. These injuries provide entrances for various rot-producing organisms. Cut off the fruit with pruning shears. Leave a one-inch stem on each fruit.
After harvesting, cure winter squash (except for the acorn types) at a temperature of 80 to 85 degrees Fahrenheit and a relative humidity of 80 to 85 percent. Curing helps to harden the squash skins and heal any cuts and scratches. Do not cure acorn squash. The high temperature and relative humidity during the curing process actually reduce the quality and storage life of acorn squash.
After curing, store winter squash in a cool, dry, well-ventilated location. Storage temperatures should be 50 to 55 degrees Fahrenheit. Do not store squash near apples, pears, or other ripening fruit. Ripening fruit release ethylene gas, which shortens the storage life of squash.
When properly cured and stored, the storage lives of acorn, butternut, and hubbard squash are approximately five to eight weeks, two to three months, and five to six months, respectively.
How do I ripen green tomatoes indoors?
Just before the first frost, remove all mature, light green fruit from the vines. (Immature, dark green tomatoes will not ripen off the vine.) They should be solid, firm, and free of defects. Remove the stems, then wash and dry the fruit.
Tomatoes that are starting to turn color (have a pink blush) can be placed on the kitchen counter or a shelf to ripen. Individually wrap tomatoes that are completely green in a piece of newspaper. Place the wrapped tomatoes in a single layer in a box and store in a cool (60 to 70 degree Fahrenheit) location. Inspect the tomatoes frequently and discard any which show signs of decay. When the tomatoes begin to color, remove the newspaper and place the tomatoes on a countertop or shelf to ripen fully.