Tiny potatoes harvested before maturity are sweet and tender, but must be eaten as soon as harvested. If you plan on storing potatoes long term, the potatoes must ripen fully before the harvest. Yellowing or dying foliage signals that potatoes are ready for digging. Under proper conditions and protection from chilling, which compromises flavor by turning potato starch to sugar, potatoes maintain their flavor and texture for up to nine months.
Harvest potatoes after the foliage dies back in the fall. Choose a cool dry day, preferably when the soil is dry. Dig with a hoe to expose the tubers.
Air dry muddy or wet potatoes until soil encrusted on the tubers crumbles when touched. Spread potatoes on the ground or on tarp in a shaded location for several hours. Dry or clean potatoes do not require air drying.
Brush or shake loose soil from potatoes--if preferred--but do not wash them. Moisture encourages rot and disease.
Place potatoes in bins or boxes and store in an area where the temperature is kept between 50 and 60 degrees Fahrenheit and humidity stays around 95 percent for two to three weeks. This hardens the outer skin and prepares potatoes for long storage.
Move the containers to a dry, dark area where temperatures are between 38 and 40 degrees Fahrenheit. If stored in a root cellar with a dirt or cement floor, keep the boxes off the floor. Doing so avoids moisture buildup and reduces the risk of chilling. Boxes may be placed on the floor in cool rooms or sheds with finished floors. The room should have good air circulation and low humidity.
Check potatoes once or twice a month for signs of rotting. Remove damaged potatoes immediately; decay spreads quickly through the entire lot of potatoes.