Root cellars, an often-ignored option for food preservation, are one of the easiest ways to store fresh, local food and save a few bucks in the process, says Barbara Salsbury, author of Beating the High Cost of Eating: The Essential Guide to Supermarket Survival (Horizon, 2005). She converted an old closet near her kitchen into a makeshift root cellar, and uses it all winter. “When good yams, cabbage, and carrots, are cheap, I buy three pounds,” she says. “When there’s a sale on squash, I buy several, and they will last for an age.”
Produce stored in a root cellar can last anywhere from a few weeks for perishables like tomatoes and watermelon to months or more for root vegetables, apples, and onions. The good news: No matter where you live, there’s a good chance you have a potential root cellar undiscovered somewhere in your home. There are essentially four key factors in a successful cool-storage operation:
1. Find a spot that’s dark and cool. Virtually any unused space can be turned into a root cellar, provided you keep out heat and sunlight. Salisbury uses a shelf in an unused cupboard, and stores overflow in her converted hallway closet. “It really does vary from household to household, depending on how well insulated a room is and where the heating vents are,” says Claire Morenon, program coordinator at the Massachusetts-based nonprofit Community Involved in Sustaining Agriculture. “It helps if there’s an outside wall,” she notes, to keep a space around 60 degrees. Even underneath a bed will work, just as long as there are no heating vents nearby, she adds. Close the heating vents and install a thermometer to monitor the temperature in your makeshift storage space. You can also try empty guest bedrooms, the bulkhead over your basement, a space beneath a porch (as long as the area stays above freezing), or even a garbage can buried in the ground outside (as long as the ground doesn’t get so cold you can’t dig it up).
2. Minimize bruising. Bruised fruits and vegetables rot more quickly, and "it helps slow down the spread of molds if they’re not touching each other,” says Morenon. Produce can also bruise if it’s resting on a shelf, so she uses a fabric shoe organizer to keep her squash from touching other squash. Another popular root-cellaring trick is to suspend items in pantyhose from the ceiling or from shelves, or to pack them in sand, which also helps keep in moisture, the next thing you need to worry about.
3. Keep it damp. Not all stored produce needs dampness in order to survive. Pumpkins, sweet potatoes, winter squash, garlic, and onions prefer low humidity levels. However, cabbage, apples, carrots, and most of your root vegetables (beets, celeriac, turnips, and so forth) like moderate to high humidity levels. You can use a humidifier if you have one, but Morenon suggests storing those crops in boxes packed in damp sand. Or you can cover a box of potatoes or root vegetables with a damp towel. The key is to remember to check periodically to dampen the towel (or sand), so the vegetables don’t dry out.
4. Sequester your apples. “Apples can’t be stored with other vegetables because they release a chemical [ethylene gas] that rots other vegetables,” says Morenon. Keep those by themselves, under a bed or in a cupboard, where they won’t interfere with the rest of your produce.
5. Dig a dirt hole.If you really want the full-blown, hard-core root cellar experience, you can build a traditional underground root cellar that takes advantage of year-round soil temperatures of about 55 degrees F. Root cellars can be entirely underground or partially underground, but the partial cellars do best if the walls not in contact with the earth face north or are shaded. Support the root cellar with rot-resistant woods. Also, it’s important to install ventilation, since stagnant air can speed up vegetable rot. For detailed instructions on creating an actual root cellar, visit Organic Gardening magazine.