Gardening Articles: Care :: Plant Care Techniques
Harvesting Potatoes (page 2 of 2)
by National Gardening Association Editors
After the Harvest
Leave the potatoes outdoors for an hour or so to dry. During that time most of the soil stuck on them should also drop off. There's no real need to brush the tubers, although some people use a very soft brush gently to take off clumps of dirt. Don't wash the potatoes; it's hard to get them really dry afterward.
Put the potatoes in the dark after they've dried in the open for a short time. Don't leave them in burlap bags or other containers where light can penetrate and start them greening.
If possible, storage potatoes should have a short drying or "curing" period of one to two weeks after the harvest. Curing allows any slight cuts or bruises on the potatoes to heal rapidly. Keep the tubers in a dark place with temperatures around 55° to 60° F with high humidity of up to 85 or 95 percent.
After a curing period, move the potatoes to a much cooler, dark place for winter storage. Experts recommend 35° to 40° F with moderate humidity and ventilation. If these standards are met in your basement or root cellar, you can expect mature potatoes to store for up to eight months. Higher temperatures will mean quicker sprouting and shriveling.
Because potatoes have to breathe in storage, a root cellar needs good air circulation The potatoes are still carrying on normal life processes, using oxygen to heal bruises and cracks and giving off carbon dioxide, heat and moisture. Good air circulation in the storage room helps this continuing process. A good way to store potatoes is in bins with slatted sides and bottoms; however, don't pile them higher than 6- to 8-inches tall.
Occasionally, potatoes turn "sweet" during storage. This happens because potatoes convert a certain amount of starch to sugar, which is used up in the "breathing" process. When the tubers are stored in cool root cellars, the breathing slows down and they don't use up all the sugar they produced. Occasionally, this extra sugar gives the potatoes a sweet taste if they've been taken directly from cool storage and cooked. However, this is rarely a problem. If your potatoes sweeten, just bring a week's supply out of storage at one time and keep them in a warmer spot. The extra sugar will revert to starch -- a process experts call "reconditioning".
A Note on Green Potatoes
When potatoes are exposed to light their skins start to turn green -- a sign that a toxic substance called solanine is developing. This occurs if potatoes aren't fully covered by soil while they're growing, if you leave them in the sun for too long after the harvest, or if they aren't stored in complete darkness. Potatoes you buy from the supermarket also turn green if they aren't stored in a dark place.
Because solanine is slightly toxic, it's possible to get sick if you have a large helping of greened potatoes. Peeling or cutting away green sections before cooking usually eliminates the problem, as most of the solanine is located in the spud's skin.