"White trash." That's how one YouTube user summed up his response to our fridge root cellar video. However, the structure cost us only about ten bucks to build and has already served up bushels of crisp carrots for a full winter with nearly no electricity, so we consider the experiment a success.
How do you turn a junked refrigerator into a root cellar? You can read the long version in my ebook $10 Root Cellar, but here are the most important factors to focus on:
Maximize ventilation. You'll need to remove dividers between the crisper area, the freezer, and the main fridge compartment. Holes in the bottom and a vent pipe at the top will keep air moving through the root cellar.
Screen out critters. All those holes I just had you drill are an invitation to mice and insects, who would love to nibble on your carrots and potatoes all winter. So screen each opening carefully to keep out the bugs.
Bury the fridge upright for ease of access. But be sure to tilt the structure slightly back and use earth anchors to prevent loose soil from pushing the refrigerator over. While you're at it, mound soil over as many sides as possible to keep the root cellar at earth temperature.
Add thermal mass. The soil you shoveled onto your root cellar will go a long way toward keeping the contents cool, but not frozen, over the winter. However, when your nights start dropping into the teens, jugs of water interspersed with your food will help mitigate cold temperatures. (As a bonus, these jugs can be used as a source of backup drinking water during power outages.)
A tiny bit of electricity can go a long way. We ended up installing a light bulb attached to a thermocube to keep the root cellar above freezing on our coldest nights, using less than 2 kilowatt-hours of electricity during our zone 6 winter. In a pinch, you can bring your root crops inside for a few cold nights if there's no electricity available. Just drape a moist towel over each basket of produce to keep the contents damp and dark.
Do you have an even lower-tech way of keeping root crops fresh over the winter? I hope you'll comment with your tips below.