If you freeze, can or dry the produce of your garden, you’ll appreciate a root cellar. It will hold many vegetables in just-picked condition for months, yet is far less work than canning and drying, and cheaper and less work than freezing. And it’s possible to consider the storage of bushels of items, instead of quarts.
What’s needed for a root cellar? Very little. It should be spacious enough for your food-saving abilities. Ten feet square is a good family size. It should be insulated off from the rest of the house, so that nearer-to-freezing temperatures can be maintained. And it should have an outside source of air. A window high up on the wall is ideal.
Remember, it’s impossible to store all vegetables together. Some require warmth and dryness, some cool, dry air. Aim for providing temperatures as close to freezing as possible, but not below freezing, and as humid as possible.
Here is the floor plan for a 10′×10′ room placed in the corner of a basement. The room has both shelves and slat bins for storage of produce, so nothing is placed on the floor, which is kept damp to increase humidity. Many persons store produce in boxes such as apple crates, believing they are easier to move in and out of the room, and result in less damage to root crops. Boxes should not be placed on the damp floor. This plan is from the Agriculture Canada publication, “Home Storage Room for Fruits and Vegetables,” and reprinted by permission.
The stress on proper insulation is shown in this cross-section view. Note in walls that the insulation is placed between studs with the vapor barrier on the outside (warm side) to prevent condensation from forming and rendering the insulation ineffective. Agriculture Canada suggests a door made with a 2×2 frame, covered with quarter-inch plywood and insulated with the same material that is used on the wall. The door should fit tightly, open out, and be weather-stripped.
Note details of insulating the ceiling, which again has the vapor barrier on the warm side, in this case nearest the floor above. An easier way to treat the ceiling is to staple a 4 mil polyethylene vapor barrier to the floor joists, making certain there are no air spaces between sheets of the barrier. Then fasten polystyrene or polyurethane board insulation below it with insulation nails.
The cross-section view of this room shows a fan and louvers set in the upper half of a basement window. These are controlled by a differential thermostat with one bulb inside the room and the other outdoors and out of the sun. This thermostat starts the fan when the outside air is cooler, and will not cut it off until the inside and outside temperatures are nearly the same, or until the inside temperature reaches a pre-selected level. The fresh air intake duct is built to expel air at nearly floor level.
A manual system is shown in the accompanying drawing, with a warm air outlet at left, and floor-level cold air inlet at right. In either case, screens and window coverings should be used to exclude insects and light. In early fall, the system is kept open during cool nights, and is closed during the day. Here are some rules for using a root cellar:
1. Time your planting of crops for the root cellar so they are as late in the season as possible. Carrots, beets and other root crops can be harvested after the first frost, and will store much better.
2. Store only sound, mature vegetables that show no signs of injury or decay. Root crops should be dry when stored. Don’t wash them before storage.
3. If loss of moisture in crops is a problem, store them in plastic bags with small perforations.
4. Check stored crops, and consign to the compost pile any that show decay.
5. To keep humidity high, sprinkle floor occasionally. And to keep boxes of vegetables off damp floor, build slatted duckwalk for them.
6. Clean out root cellar each summer; wash inside and scrub all containers.
