Potatoes are one of my favourite crops, and each year I grow a selection of different varieties. I do well enough growing great potatoes, but potato storage stumped me for years. The house is too warm and the refrigerator is too cold, plus you're fighting Mother Nature. The natural dormancy period for most potatoes is only two to three months, so storing potatoes through winter involves a bit of botanical trickery.
And boy, do I need tricks. In my climate, spring-planted potatoes mature in July, which allows enough growing time for replacement crops like fall broccoli or kohlrabi. As for storing potatoes through summer, the best method I have found is to lift them from the row and immediately bury them in broad trenches so they are covered with 6 inches (15 cm) of loose soil. I cover the mound with several folds of newspaper to help it shed excess rain. The buried potatoes wait out warm weather in cool, moist soil, and can be handled like newly harvested potatoes when the soil begins to cool in the fall.
The Art of Curing Potatoes
Potato varieties vary in the thickness of their skins. Most red-skinned potatoes and fingerlings have thin skins, while big russets and many other brown-skinned potatoes have thicker coats. In between are many multi-purpose potatoes like the purple potato I've been growing for years. When nicely cured, it develops a very thick skin, which is a top characteristic of a good storage potato. All potatoes lose moisture in storage, but those with thick skins stay sound longer.
Hence the need to separate potatoes by type as they come in from the garden, and give each an appropriate curing period – usually 7 to 10 days. Before curing potatoes, I lightly rinse them in cool running water to remove excess soil, but I make no attempt to remove soil from eyes and crevices. Serious scrubbing should always be delayed until just before the potatoes are cooked.
After patting the spuds dry, I lay them out in a cool, dim room covered with a cloth or towels to block out sunlight. During this time the skins will dry, small wounds will heal over, and new layers of skin will form where the outer layer peeled or rubbed off. Thin-skinned potatoes cure faster than those with thick skins, which may benefit from a few more days of curing time.
Sorting and Storing Potatoes
My favourite fingerlings don't hold up well in storage no matter how well they are cured, so I set these aside for eating in the fall, and keep the little darlings in a cardboard box under my bed. I sort my other cured potatoes by type, and place them in small cardboard boxes or bins, which are moved to the basement where winter temperatures average around 55°F (13°C). There they stay until they are gone.
Unfortunately, displaying your beautiful potatoes in a bowl on your countertop will not do. In addition to turning green from light exposure, warm temperatures encourage potatoes to break dormancy and start sprouting. In a potato storage study from the University of Idaho, students took potatoes home and stored them in various places, ranging from a kitchen countertop to the refrigerator to a box in an unheated garage. Unheated spaces like basements and garages with average temperatures around 55°F (13°C) gave the best results. When refrigerated, potatoes develop sugars that cause them to darken when cooked.
Commercial potato storage facilities keep temperatures at 45°F (8°C), but the constant cool temperatures in caves such as those in the southern Cappadocia region of Turkey have proven to be ideal places for storing potatoes. In the US, early settlers from Tennessee to Oklahoma used caves for storing potatoes and other crops. In the state of Missouri alone, eight caves bear the name, Potato Cave. Of course a root cellar would be ideal, but I'll never grow enough potatoes to justify such a huge project. Instead I exploit the most cave-like places I can find in my house for storing potatoes, be they in the basement or under my bed.
By Barbara Pleasant