It’s awesome that there are a bunch of fruits and vegetables that don’t need to be frozen, dehydrated, or canned to keep in good condition for future consumption. Under the right conditions, a good variety of foods can be stored for up to six months or more in an appropriate root cellar. Of course there’s a hitch. Not every food likes the same conditions!
What’s the basic concept?
A root cellar is a climate-controlled space optimized to store certain foods such as root vegetables–hence the name!
What can be stored?
Potatoes, carrots, parsnips, beets, turnips, brassicas (cabbage, cauliflower, kale, etc), pumpkins, winter squashes (butternut, acorn, etc), onions, garlic, leeks, apples, and pears. This is not a conclusive list, and the length of time these items will last varies.
Make sure that you only try to store blemish-free produce. Not only does one bad apple spoil the whole box, the same is true of one bad potato or one bad carrot. If you have less-than-perfect produce, pack it separately and use it first.
What constitutes a root cellar?
1. Covered rows in the garden: Carrots, parsnips, and turnips can be left in the garden throughout the winter, at least if rodents aren’t a problem. When the ground is cold in the fall, cover the rows with loose hay a foot deep. Mark both ends of the row with tall sticks so you can find them when snow is knee deep! Just remove the hay, dig up part of the row, pile the hay back, and carry on.
2. Holes in the ground: Dig a hole large enough for a new, clean metal or plastic garbage bin, deep enough that just the lip of the container is above ground. Poke a few holes in the bottom for drainage. Then layer root vegetables with insulating layers of straw. When you’re done, put the lid on the container and mound at least a foot of straw or hay over it, including the area up to 2′ beyond the bin’s edges.
3. Unheated cellar/basement space: If you have a space that stays between 34 and 40 degrees Fahrenheit, preferably with a bit of humidity, you can store potatoes, carrots, other root crops, apples, and pears for months. Apples give off ethylene, so you may want to separate them from the vegetables as the gas causes potatoes to sprout more quickly. Onions and garlic prefer less humidity, but still like it cool.
4. Warm, dry space: A dry space in the 55-60 Fahrenheit range is perfect for pumpkins and other squashes. I’ve kept these under the spare room bed or the top shelf in a closet.
5. A full-on root cellar: These are often dug into a hillside, held up with logs or rocks, and covered with dirt on three sides (often part of the fourth as well.) With a door to the outside and shelves lining the “walls,” these often offer the most customizable space. If you’re in the market to build such a unit, do a bit of research to understand the required ventilation, etc.
Want more info?
This .pdf file from Washington State University gives a more-in depth look at the principles and practical aspects of root cellaring than I have here.