Harvest potatoes from the ground once the green stems turn brown. If the temperatures are hotter than 70 degrees Fahrenheit during harvest time, keep them in the ground until it cools down to about 59 to 68 degrees Fahrenheit during harvest, advises the Food and Agriculture Organization of the United Nations.
Place the harvested potatoes in a shady area of the yard for five to 10 days to cure. The potatoes should be stored outdoors to provide the curing process enough heat and humidity to slightly dry them out before storage, according to the Food and Agriculture Organization of the United Nations. Cover the pile of potatoes with straw and then with a burlap sack. Shade is required, because sun will damage the potatoes and make them dangerous to eat, according to the Old Fashioned Living website.
Brush potatoes with a dry brush to get off excess soil. A light layer of soil is okay for storage and will help them keep longer. Do not wash the potatoes with water because water causes mold to develop.
Place the potatoes in the root cellar, stacking if necessary, in a wooden container or bin. The cellar temperature should be a constant 40 degrees so that the potatoes don't spoil, according to the University of Missouri Extension website. Cover them with a burlap sack or straw to allow air to flow around the potatoes during storage.
Eat the potatoes within four to six months after storage.