Richard Jauron
Extension Horticulturist

Summer vegetables can still be harvested late in the season, but it is important to know when to harvest. The following are some tips that can help.

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 4 to 6 months.

When should I harvest Brussels sprouts? 

Wait until the plants have been exposed to one or more light frosts or freezes. Temperatures in the upper twenties and low thirties improve the favor of Brussels sprouts. The sprouts have a milder, sweeter favor. Harvest individual sprouts from the base of the plant as they become solid. Sprouts should be 1 to 1½ inches in diameter and tender and green. Remove the sprouts higher up on the plant as they become firm. Do not strip the lower leaves from the plant as they are necessary for further growth.

Sprouts can be placed in a plastic bag and stored in the refrigerator for 2 to 3 weeks.

How do I ripen green tomatoes indoors? 

Just before the first frost, remove all mature, light green fruit from the vines. (Small, dark green tomatoes will not ripen off the vine.)  The tomatoes 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 counter top or shelf to fully ripen.

Iowa State University Extension & Outreach

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