With proper storage, many fruits and vegetables can last through the winter months, greatly expanding the effectiveness of your garden harvest or allowing you to take advantage of local produce when it is inexpensive during its peak season. Most vegetables and fruits require near-freezing, moist winter storage conditions and can be kept in an extra refrigerator; other fruits and vegetables require cool, moist conditions and keep well in a basement or garage.
Select the best quality, unbruised fruits and vegetables just at the peak of ripeness or maturity for winter storage. Sort those fruits and vegetables which require the coldest (32 degrees Fahrenheit) moist storage (including apples, pears, root vegetables like carrots, potatoes and beets, and greens like cabbage, parsley and celery) from those requiring cool (50 degrees F) moist storage (such as beans, tomatoes, cantaloupe and melons), and those requiring cool (50 degrees F) dry conditions, like hot peppers, pumpkins, squash, and sweet potatoes.
Install spare refrigerator in a cold location such as a protected porch or unheated garage. Plug it in and set it to its coldest setting. Place a 6-inch layer of sawdust in the lower drawers or vegetable bins of the refrigerator. Saturate the sawdust well with tap water.
Place fruits and vegetables requiring cold, moist storage in plastic bins. Pack sawdust around the fruits and vegetables, and moisten the sawdust with tap water. Put the lids on the bins and place the bins in the refrigerator. List the contents of each bin on a piece of paper using permanent marker. Affix these sheets of paper to the outside of the refrigerator with packing tape to help minimize the amount of time the refrigerator door is open when removing stored produce.
Place fruits and vegetables requiring cool, moist storage into wooden crates or bushel baskets, layering the produce with 2-inch layers of sawdust moistened with tap water. Stand concrete blocks on end in a cool location which does not reach temperatures below 40 degrees, such as in an insulated porch or unheated portion of a basement. Lay lumber planks across blocks to make a shelf; stack additional concrete blocks and planks as needed to create enough shelves for storage. Place wooden crates or bushel baskets of produce on the shelves. Staple a heavy-mil plastic sheet to the top shelf with staple gun and staples to create a curtain on either side of the shelves of produce to retain moisture.
Create additional concrete block and lumber plank shelves in a cool, dry location such as a house attic or pantry. Place onions and garlic in bushel baskets or wooden crates on the floor of this dry location, as they like chillier dry storage. Set individual pumpkins and melons on shelves with space between them for air circulation. Set sweet potatoes in bushel baskets or wooden crates on the top shelf, as they can tolerate slightly warmer storage.