Root Cellar Basics

What does a root cellar do?

It holds produce in conditions that slow ripening and decay. The key conditions are cool temperature, high humidity for most root crops, darkness, and some air movement to carry away gas and warmth.

Different crops want different conditions, so most cellars have zones. A cellar that is too warm, dry or stagnant will not do its job.

Ask your extension office for target ranges for each crop, since they vary and I will not state numbers. Think of the cellar as a system. Temperature, humidity, airflow and the crops you place inside all affect each other, so small changes in one need a check on the others. A good first step is to sketch your house and yard and note where it stays coolest in winter without freezing.

• Cool
• Humid
• Dark
• Ventilated

What can I store?

Potatoes, carrots, beets, turnips, parsnips, cabbage, winter squash, apples and onions are common crops, but they do not all like the same spot. Cabbage and apples give off odors and gases that affect others, so store them separately.

Only store sound produce. A single rotten item can spoil neighbors, so sort carefully and discard any with damage.

Check a crop-by-crop guide before you fill the cellar. Different crops also have different needs for curing before storage, so cure onions, squash and potatoes as their own guides describe before they go downstairs. Keep onions and garlic in a drier corner than the root crops, since they dislike damp air.

Where can I build or set up one?

Options include a basement corner with an outside wall, an unheated room, a buried container, a purpose-built cellar or an insulated crate in a garage. The best choice depends on your climate and house.

Excavation, structural work, electrical and ventilation changes may need permits and licensed professionals, and local rules vary by town and county. Ask your local building or zoning office before digging or altering a structure.

Never enter a closed cellar or pit with poor air without a plan for ventilation, since air can be unsafe in enclosed spaces. Local building codes may cover egress, ventilation and moisture control for any room you convert, so a short call to your town office before you start can save money and rework. Choose a location that is easy to reach in bad weather, because you will visit it often.

How do I manage humidity and ventilation?

Most root crops store best with high humidity, which a dirt floor, damp sand or covered containers can help provide. Ventilation lets warm air and ethylene gas escape and brings in cool outside air.

A thermometer and a hygrometer help you track conditions. Adjust vents as the weather changes, opening when it is cool outside and closing when it is cold enough to freeze produce.

Avoid standing water, which brings rot and pests. Keep a record of readings through the first winter, then adjust vents and layout the next year. A cellar usually improves as you learn its habits.

How should I pack and arrange produce?

Use slatted crates, boxes or bins so air can move. Layer roots in damp sand or sawdust if your source recommends it, and keep cut or damaged items out. Leave space between containers.

Label crates with crop and date, and put the items to use first at the front.

Keep produce off the floor and away from walls where moisture or frost can form. Avoid wooden crates that were treated with chemicals, and use food-safe materials for anything that touches produce.

How do I check and use stored crops?

Inspect regularly, at least every couple of weeks, removing anything that is soft, moldy or sprouting. Use the most perishable first. Keep a simple log of condition and temperature.

Wash stored vegetables before use. Discard anything with mold or a strong odor.

If you find evidence of mice or insects, address it with methods your extension office recommends. A weekly walk-through is a small habit that prevents a big loss, since one soft potato or rotting apple can affect a whole bin within days.

What mistakes should I avoid?

Storing unsound produce, storing apples with potatoes, letting the cellar freeze or overheat, and ignoring ventilation are the main ones. Another is overfilling, which blocks airflow.

Start small, keep notes on your conditions, and adjust each year.

If you are unsure about a crop, ask your county extension office. If your cellar has a dirt floor or damp walls, ask about radon and moisture testing through your health department or extension office, particularly if the cellar connects to living space.

Last reviewed: November 12, 2026. Written by the Homestead & Small Farm Editorial Team. See our editorial policy.