Root Cellar and Cold Storage for Squash, Potatoes and Apples

Before refrigerators, most households kept a winter’s worth of potatoes, squash, apples and root vegetables in a cool, dark room. That skill still matters. Food kept this way uses no power, so a long outage does not touch it, and it stretches a pantry of dry and canned goods with fresh food through the cold months.

You do not need a classic dug-out cellar. This guide covers what potatoes, winter squash, apples and root crops each need, and where to find those conditions in an ordinary house. The figures come from University of Missouri, Iowa State, University of Minnesota (UMN) and UConn Extension. I have not run a root cellar myself.

The rule that matters most: separate the fruit

University of Missouri Extension says not to store apples with vegetables. Apples and pears give off ethylene gas as they ripen, which shortens the storage life of vegetables, and potatoes stored near fruit may sprout early. Iowa State gives the same warning for winter squash and for potatoes.

So plan for at least two spots: one for fruit and one for vegetables. Missouri also notes that strong-smelling crops like cabbage and turnips can pass their odour to fruit and other food, so give them their own corner too.

What each crop wants

Crop	Temperature	Humidity	Source
Apples	32 to 40°F (0 to 4°C)	80 to 90%	Missouri
Potatoes	about 40°F (4°C), dark	90 to 95%	Iowa State
Carrots, beets, cabbage, parsnips, rutabaga	32 to 40°F (0 to 4°C)	90 to 95%	Missouri
Onions and garlic	32 to 35°F (0 to 2°C)	60 to 70%	Missouri
Winter squash and pumpkins	50 to 55°F (10 to 13°C)	60 to 75%	Missouri

Missouri adds that late-maturing crops store better than early ones, that well-cured, undamaged produce lasts longer, and that nothing in storage should be allowed to freeze.

Potatoes

Cure first. Iowa State says to cure potatoes for two weeks at 50 to 60°F (10 to 16°C) and 85 to 90% humidity. Curing heals small cuts and bruises and thickens the skin.

Then store cold, humid and dark. Iowa State gives about 40°F (4°C), 90 to 95% humidity and no light. Light turns potatoes green, and UMN Extension says to trim green areas and not to eat potatoes with a lot of green. UMN also says potato sprouts can be toxic and should not be eaten.

Watch the temperature. Above 50°F (10°C), Iowa State says tubers may sprout within two or three months. Below 40°F they turn sugary; a few days at room temperature restores the flavour. Iowa State gives a storage life of 5 to 8 months under good conditions.

Winter squash

Cure most kinds. Iowa State says to cure winter squash at 80 to 85°F (27 to 29°C) and 80 to 85% humidity, which hardens the skin and heals scratches. Acorn squash is the exception: high heat and humidity reduce its quality and storage life, so skip curing it. UMN says not to cure Table Queen, which is an acorn type.

Store cool and dry, not cold. Iowa State gives 50 to 55°F (10 to 13°C) in a dry, well-ventilated place, away from apples, pears and other ripening fruit. UMN says pumpkins are very sensitive to temperatures below 45°F (7°C).

Know your variety. Iowa State’s storage times: acorn 5 to 8 weeks, butternut 2 to 3 months, Hubbard 5 to 6 months. Eat the short keepers first.

Apples

Missouri lists apples in the cold and moist group, 32 to 40°F (0 to 4°C) and 80 to 90% humidity, and the instruction that matters most is to keep them away from vegetables. UConn notes that apples prefer more humidity than onions and garlic.

Root crops

Missouri puts beets, cabbage, carrots, parsnips, rutabaga and turnips in the cold and very moist group, 32 to 40°F (0 to 4°C) and 90 to 95% humidity. UMN says carrots and beets store without their tops and gives about 8 months for carrots and 5 for beets.

UConn says carrots, parsnips and turnips can also stay in the garden over winter if rodents are not a problem and the site drains well, insulated with straw, hay or dry leaves once the ground cools.

Where to find these conditions at home

UConn Extension suggests looking at:

• An unheated garage, breezeway or shed, kept away from cars, lawn equipment and chemicals, and only while there is no risk of freezing.
• A cool corner of a basement. UConn says a well-ventilated basement at about 50 to 60°F (10 to 16°C) suits short-term storage of squash, pumpkins, potatoes and onions.
• An unheated room, pantry or attic for short-term storage of potatoes and onions, again only if it will not freeze.
• Outdoors, in a buried 20-gallon (about 75 L) trash can with drainage holes, which UConn says can help deter rodents. Once a pit or mound is opened, UConn says to use the produce within one or two weeks.

A cheap thermometer in each spot tells you which crops belong where. Squash usually goes in the warmer spot, potatoes and roots in the coldest damp one, and apples somewhere separate.

Keep pests out and check weekly

UConn advises:

• Sealing gaps, even very small ones, with steel wool.
• Using metal, plastic or tightly woven mesh containers with openings smaller than ¼ inch (6 mm), and only food-grade containers.
• Checking storage at least weekly for signs of rodents and drying out.
• Removing anything rotten or mouldy, and cleaning containers and the room at the end of the season.

Dry staples belong somewhere else

Rice, dried beans, oats and powdered milk do not want root cellar humidity. They keep best somewhere cool and dry, in sealed food-grade containers that keep out moisture and pests. My post on pantry staples that keep a year covers official storage times and where to keep them, and pantry rotation explains how to use the oldest first.

Putting it together

A cold room full of potatoes, squash, apples and carrots, next to a dry pantry of rice, beans and cans, can carry a household a long way through winter without any power at all. For what to grow, see 10 easy vegetables that store well and how much to plant to feed a family. For how much food your household needs in total, use the plan builder and the food section, and for meals built on pantry staples, browse the recipes, such as one-pot rice and beans.