A root cellar provides natural cold storage for vegetables, fruits, and preserved foods using the earth's stable temperature. Root cellars maintain temperatures of 0 to 10 degrees Celsius (32 to 50 degrees Fahrenheit) and humidity of 85 to 95 percent, conditions that slow respiration, sprouting, and spoilage. Root cellaring is the most energy-efficient method of [[Food Storage]], requiring no electricity. A well-managed root cellar keeps root vegetables fresh for 4 to 8 months.
Root vegetables including carrots, beets, turnips, parsnips, potatoes, and onions store well in root cellars. Cabbage, winter squash, and pumpkins also store for extended periods. Apples and pears store for 3 to 6 months but release ethylene gas that accelerates ripening of other produce, so they are stored separately. Garlic and onions are stored in a dry, well-ventilated area rather than the high-humidity environment of a root cellar.
Different crops require different storage conditions. Potatoes are stored at 4 to 7 degrees Celsius (40 to 45 degrees Fahrenheit) in complete darkness to prevent greening. Onions and garlic require 0 to 4 degrees Celsius (32 to 40 degrees Fahrenheit) with low humidity and good air circulation. Winter squash and pumpkins are stored at 10 to 13 degrees Celsius (50 to 55 degrees Fahrenheit) to prevent chilling injury. Carrots and beets are stored in damp sand or sawdust to prevent shriveling.
Produce is inspected regularly and any spoiled items are removed immediately to prevent spread. The cellar is ventilated during cool weather to maintain temperature and remove ethylene gas. Temperature is monitored with a maximum-minimum thermometer. Humidity is maintained by watering the floor or using damp sand. The cellar entrance is insulated and sealed with weatherstripping.