Onions, potatoes and winter squash store well all winter when left to sit in a dry, warm and sheltered area for a week or two before storing. Good locations for curing might be a box in a dry basement or garage, or simply covered on a dry porch.
• Onions: After harvesting bulbs, set them in the sun for a day or two (cover at night). Next, cure bulbs with tops intact for about a week in a sheltered, dry area; during this time, the outer layers form a dry skin. After that, cut tops about an inch above the bulbs, trim off roots and store onions in a well-ventilated, dry, cool (ideal is 35 to 40 degrees) and dark location for up to a year.
• Winter squash: Cure fruits in a warm place (80 to 85 degrees is ideal) for a couple of weeks. Once cured, store in a cool, dry location at 50 to 55 degrees for up to four months.
• Potatoes: After digging potatoes, allow them to dry for a few hours in the sun, then cure them for about two weeks at 50 to 60 degrees under shelter in a well-ventilated, high-humidity area. After they are cured, potatoes store best at 35 to 40 degrees, but keep well for several months even at 50 degrees.