If you live in a climate where the winter temperature averages 30°F. or lower, you can enjoy the benefits of a root cellar. Vegetables and fruits store better where the air can be kept damp and the temperature as low as possible without freezing. It is much easier to maintain an even temperature if the storage cellar is underground.
You may build the cellar so the whole structure is completely underground, or so the soil is banked up around three walls leaving one wall and the roof exposed, or so the cellar is completely above the ground and covered with sod. However you build it, the walls and roof must be strong enough to hold the weight of the earth. Stone or brick, reinforced with concrete, cement blocks, or reinforced concrete can be used.
The air must be kept moist to prevent the produce from shrinking. Put wet sawdust or straw on the floor, or stand a pail of water under the air intake vents. Perhaps the best way to maintain moisture and prevent shrinkage is to store produce in polyethylene bags or box liners in which you have cut a few 1/4″ to 3/8″ holes to allow for ventilation. Onions should be hung from the ceiling in open mesh bags to allow plenty of air to circulate around them. The cellar must be dark. Sunlight turns potatoes green and bitter to the taste.
If you are storing both fruits and vegetables, compartments should be built to keep them separate. There should be an air intake or ventilator for each compartment. Screens over the ventilator or air intake will keep out birds and rodents.
Fruits and vegetables may require varying types of humidity, temperature, and ventilation to control moisture and vitamin loss and to maintain flavor, but a few basic rules apply to almost all storage:
Handle the fruits and vegetables carefully to prevent damage. Use slatted containers with no nails, staples, or wires protruding to damage the produce. Standard boxes used for shipping fruits are good storage containers.
Sort out damaged fruits and vegetables to prevent serious loss from decay.
Harvest when temperature is cool, or allow the crops to cool outdoors overnight before storing.
Prevent freezing—most vegetables store best between 31–35°F., so if you keep the temperature around 32°F., fruits and vegetables will keep well. A 100-watt light bulb near the floor will prevent freezing when the outside temperatures are low.
Moveable slats on the floor prevent spoilage by keeping storage containers away from direct moisture and allowing ventilation.
For specific helps on the best ways to store fruits and vegetables in your areas, write for the booklet Storing Vegetables and Fruits in Basements, Cellars, Outbuildings, and Pits, Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. A plan for an underground cellar, identified as plan 5948, may be obtained through your county or state agricultural service or through your state agriculture service. (Give the plan number when ordering.) There is usually a small charge for the booklet or plans. Shirley Nielsen, Church Welfare Services