The quick root cellar

What a root cellar does

Before refrigerators, families kept a winter's worth of vegetables and fruit fresh using nothing but the earth. A few feet down, the ground stays cool and steady all year, and moist soil keeps the air humid, so produce stays crisp instead of shriveling.

A root cellar won't preserve food forever, but done right it keeps potatoes, carrots, beets, cabbage and apples for 2 to 6 months with no power at all. In a long emergency it turns a fall harvest, or a bulk buy of produce, into fresh food all winter.

The conditions crops need

Most root crops want it cold, damp, dark and ventilated: about 32 to 40°F and high humidity. Not every crop agrees, so group them.

• Cold and very moist (32–40°F, 90–95% humidity): carrots, beets, turnips, parsnips, rutabagas and radishes.
• Cold and moist (32–40°F, 80–90% humidity): potatoes, apples, pears and cabbage.
• Cool and dry (50–60°F, 60–70% humidity): winter squash and pumpkins. They rot in a damp cellar, so keep them in a cool bedroom or closet.
• Cold and dry (32–40°F, 60–70% humidity): onions and garlic. Hang them in mesh bags somewhere cool and airy.
• Too cold is as bad as too warm: frozen produce turns to mush. Keep a thermometer and a humidity gauge in the cellar.

Quick option 1: the buried can

The fastest real root cellar is a clean metal garbage can or a food-grade barrel buried in the ground. It holds a few bushels and can be dug in an afternoon.

• Pick a well-drained spot that never puddles, out of full sun if possible.
• Dig a hole a little wider than the can and deep enough that the rim sits a few inches above the ground, so surface water can't run in.
• Drill a few small drainage holes in the bottom and put a few inches of gravel in the hole.
• Set the can in, backfill around it, and layer produce inside with straw, dry leaves or damp sand between the layers.
• Put the lid on, cover it with a thick mound of straw or leaves (1 to 2 feet), and top that with a tarp or board to shed rain.
• Metal keeps mice out. A plastic barrel works if you wrap it in hardware cloth.

Quick option 2: the clamp, or storage pit

A clamp is the old farm method: a mound of vegetables insulated with straw and soil. It costs nothing but labor. Several small clamps beat one big one, because opening one leaves the rest sealed.

• On well-drained ground, dig a shallow pit 6 to 12 inches deep and line it with straw, with hardware cloth underneath to stop rodents.
• Pile root crops or cabbages in a cone, keeping different kinds apart if you can.
• Cover with a thick layer of straw, then several inches of soil. Leave a twist of straw poking out of the top as a vent.
• Dig a small trench around the mound to carry rainwater away.
• In very cold areas, add more straw and soil as winter deepens. Open it on a mild day, take what you need, and re-cover it quickly.

Quick option 3: a basement corner

If the house has an unheated basement, the cheapest cellar is often a corner of it.

• Choose the north or northeast corner, away from the furnace, and wall it off with insulated walls and an insulated door, so the outside walls keep it cold.
• Add two vents: a low one that brings in cold outside air and a high one that lets warm air out. Open and close them to control the temperature.
• A dirt or gravel floor helps hold humidity. On concrete, use bins of damp sand or sprinkle the floor with water.
• Keep produce on slatted shelves off the floor so air can move around it.
• An old chest freezer buried in the ground also works as a cellar. Remove or disable any latch first so a child can never be trapped inside.

Getting the harvest ready

• Store only sound, unbruised, full-size produce. One rotting potato spoils the ones touching it.
• Don't wash root crops. Brush off loose soil and let them dry.
• Cut carrot and beet tops off, leaving about an inch of stem.
• Cure potatoes first: keep them in the dark at 50 to 60°F with high humidity for about 2 weeks so the skins toughen.
• Cure winter squash somewhere warm (around 80°F) for about 10 days before storing it cool and dry.
• Pack carrots, beets and other roots in boxes of slightly damp sand, sawdust or peat so they don't dry out.

What not to store together

Apples, pears and some other fruit give off ethylene gas, which makes potatoes sprout and turns carrots bitter. Keep fruit and vegetables in separate spaces, or at least at opposite ends of a well-ventilated cellar. Cabbage and turnips give off strong smells that apples soak up, so keep those apart too.

Digging safely

• In the US, call 811 a few days before you dig. Utilities will mark buried gas, power and water lines for free.
• Keep away from low spots, septic fields and wells.
• Fence or cover any open hole so children and animals can't fall in.
• Check the cellar every week through the winter and remove anything rotting. Rot gives off heat and moisture and spreads fast.