By Richard Jauron, Greg Wallace
As Iowa gardeners dig into the produce they harvested in the fall, they may be having issues with produce storage, leading to disappointment.
Here are some tips from Iowa State University Extension and Outreach horticulturists on why produce problems are happening and how to avoid them. To have additional questions answered, contact the ISU Hortline at 515-294-3108 or hortline@iastate.edu.
My acorn squash have turned yellow during storage. Why?
The problem may be improper storage. Acorn-type squashes should be stored at a temperature of 50 to 55 degrees Fahrenheit. Some acorn-type squashes will turn yellow when stored at temperatures above 55 F. High storage temperatures also may cause the flesh to become stringy.
Why are my potatoes beginning to sprout?
Potatoes should be stored at a temperature of 40 F and relative humidity of 90 to 95 percent. Tubers often begin to sprout if storage temperatures are above 50 F. Also, don’t store potatoes with apples or other fruits. Fruits produce ethylene gas. Ethylene promotes sprouting of potatoes.
My sweet potatoes have become dry and stringy. What caused this?
It’s likely the sweet potatoes were not cured and stored properly. After harvest, sweet potatoes should be cured for seven to 10 days at a temperature of 80 to 85 F and relative humidity of 80 to 90 percent. (These conditions are difficult to find in the typical home. Select a site that comes as close as possible to these conditions.) Curing promotes healing of minor cuts and bruises, prolonging the storage life of the 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 F and relative humidity of 85 to 90 percent. Sweet potatoes stored at temperatures above 60 F will shrivel and become dry and stringy. Sweet potatoes may develop an off-flavor and the flesh may become discolored when stored at temperatures below 55 F.
My onions don’t store well. Why?
The storage life of onions is largely determined by the variety (cultivar), harvesting and drying procedures, and storage conditions.
When selecting onions, choose cultivars that store well, such as ‘Copra,’ ‘Stuttgarter’ and ‘Red Zeppelin.’ ‘Walla Walla,’ ‘Candy,’ and ‘White Sweet Spanish’ are poor keepers.
Harvest onions when most of their tops have fallen over and begun to dry. After harvest, dry or cure the onions in a warm, dry, well-ventilated location for two to three weeks. When the onions tops are dry, cut off the tops 1 inch above the bulbs.
Place the cured onions in mesh bags, crates, or wire baskets and store in a cool (32 to 40 F), dry location. Onions will sprout if storage temperatures are too warm. The bulbs may rot in damp locations.
Source:iastate.edu