How to Build a Root Cellar

Types of Root Cellars

Sandy Newton
Potatoes in root cellar

Before refrigeration, the root cellar was an essential way to keep carrots, turnips, beets, parsnips, potatoes, and other root vegetables fresh through the winter months.

If you have snowy, wintry conditions, this time-tested storage method still makes sense today—whether you stock a root cellar with your own homegrown produce or the bounty from local farmers’ markets.

What is a Root Cellar?

Technically, a root cellar is any storage location that uses the natural cooling, insulating, and humidifying properties of the earth.

  • To work properly, a root cellar must be able to hold a temperature of 32º to 40º F and a humidity level of 85 to 95 percent.
  • The cool temperatures slow the release of ethylene gas and stop the growth of microorganisms that cause decomposition.
  • The humidity level prevents loss of moisture through evaporation—and the withering look that goes along with it.

Basement Root Cellars

Today, root cellars are often attached to houses for easy access, though it can take some effort to create a cold basement corner.

  • The best method is to use the foundation walls on the northeast corner as two sides of your root cellar.
  • Build the other two walls in the basement with stud and board.
  • Insulate the interior walls, ceiling, and door (and any pipes or ducts) to keep the heat out.
  • Ensure there is a ventilation system that allows cool, fresh air from the outside to be brought into the root cellar and stale air to be exhausted out.

Hole-in-the-Ground Cellar

Another option outside the house is to dig down into the ground or horizontally into a hillside. 

  • This option requires good drainage; sandier soil works better. An elevated slope helps because the water will run away from your pit as it moves downward.
  • If your winter temperatures drop below 25°F, dig your pit deep enough so that all the crops are under the soil’s surface. 
  • As you dig your hole in the ground, flare the sides so that it does not cave in. 
  • Line the hole with straw and dried leaves, cover the hole with a thick wooden lid, and cover the lid with soil.

The Garbage Can

During the wintertime, using a metal garbage can or barrel in your hole-in-the ground cellar helps keep water out.

  • Dig a hole slightly larger than the diameter of the garbage can and deep enough so that the can’s lid will sit 4 inches above the soil level.
  • Heap earth around the circumference, add straw inside the can with the crops, and cover the lid with straw or mulch and a sheet of plastic to keep everything dry.
  • Root vegetables will store well, even in the coldest weather.

How to Keep It Cool

To create the best atmosphere in your root cellar, consider this:

  • Complete temperature stability is reached at about 10 feet (3 m) deep.
  • Don’t dig a root cellar near a large tree; the tree’s roots can be difficult to dig through, and they will eventually grow and crack the cellar walls.
  • Inside, wooden shelving, bins, and platforms are the norm, as wood does not conduct heat and cold as rapidly as metal does.
  • Air circulation is critical for minimizing airborne mold, so shelves should stand 1 to 3 inches (3 to 8 cm) away from the walls.
  • For outdoor root cellars, packed earth is the preferred flooring. Concrete works well and is practical for a cellar in a basement.
  • Every root cellar needs a thermometer and a hygrometer (to measure temperature and humidity, respectively), which should be checked daily, if possible.
  • Heat is usually regulated using ventilation to the outside or an exhaust pipe—usually to allow cold air in, often on fall nights to get the temperature down.

Source: 

The 2003 Old Farmer's Almanac Canadian Edition

Reader Comments

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Root Cellars;

Root Cellars; Maple Sugar Houses; old Ice houses; good to see some returning to use; a true root cellar is a stone type hut with most of the stone house under the ground; we had quite a few root cellars in Fairfield Conn.; at one time; one historical root cellar can be seen nearby;
(I will try to get a picture; + contact to house owner to tell him he a root cellar treasure house):

Root Cellars; Farms;

Fairfield Conn. is a Historical "Onion farming town"; Root Cellars were essential to the original settlers/farmers to live in New England;

Root Cellar/ cooler

When I was a kid, our house has what the called a cooler. it was cabinet that had vents to the outside, has anyone seen this or use something like this for veggies/fruit? I was thinking that I want to build something like that here. I live very close to sea level, so a cellar is not an option.

Old root cellar

In our 1793 dirt floor cellar is a brick walled root cellar. My husband has been digging out the dirt to put in concrete and found a layer of broken glass in the walled in storage room. Was there a reason to line this area of the floor with glass, maybe to keep the rodents from digging in?

Crushed Glass in Root Cellar

It’s possible the crushed glass was used for drainage purposes–though that is just a guess!

crushed glass in a root celler

Glass bottles were often laid in the floor then covered with soil or motor to act as a layer of insulation. The space they created kept the floor warmer. They were also used in pig stalls in England during the Victorian era.

Broken glass in dirt cellar floor

Thanks for the thoughts. As he has been digging out the entire cellar floor out to the corners, my husband has come across broken glass, including pottery and dishes, underneath the dirt. It may have been insulation or a rodent deterrent, but it seems to be the entire floor.

root cellar

i live in the Richmond Va area and want some input for a potato bin, i am considering using a large aluminum truck tool box i have laying around. it has a hinged lid. i was going to bury it in the woodline of my property to keep it out of the direct sun and approx 3 ft deep withe the lid just above ground level to keep rain out. i was going to add a vent pipe to the lid for air circulation. any thoughts

Root Cellar

Hi Doug,

That is a very clever idea! Just be sure to line the bin with straw for insulation. And cover the lid with a tarp to prevent water from leaking in.

potato bin

lining it with straw & tarping was my thought too. thanks for the input

Could I use filing cabinets in a basement?

I live in an old house in NH, built in 1840, and we have a basement that has been dug out and lined with concrete and is in good shape. I have been thinking of building a root cellar in the basement utilizing a corner that stays at a constant temp and humidity. However in a store that is just up the street from us I have seen a line of old filing cabinets for sale. Could the cabinets be used in the basement for storing veg?

storing vegetables

Filing cabinets, especially metal ones, might not be a good idea to store vegetables over the long term, as they need air circulation to help prevent mold and other diseases. You might be able to modify the cabinets, such as remove the front part of the drawers and replace with wire mesh, but there are other containers that might work better, such as baskets, or cardboard or open wooden boxes.

Can I convert a cement silo into a root cellar?

We bought a home that has a VERY well kept cement silo with a steel 'cap' on top. It has a dirt floor and the steel cap roof has a gap for ventillation. Its a lovely structure that is in great condition. We'd like to use it for something useful- but are not sure what? There are no 'windows', so no light (which took away our idea of turning it into a chicken coop), but we have been researching if it could be used as a root cellar? Any thoughts if this would work? Or what things would we have to consider before deciding if it would offer the right 'conditions'? ps- we live in Wisconson where winters get very cold.
thanks

Basement root cellar ventilation

We are building a root cellar into a new home construction. The root cellar will have 3 exterior walls, and will be over 12 feet long. All pics I have seen put both vents side by side, is that necessary? Can we place them on opposite walls, in order to distance the inlet from the outlet? Instead of the long horizontal pipe found near the floor on the inlet pipe, we would separate the vents at the top, and put a downspout on the inlet to take the cold air down.

When you say the root cellar

When you say the root cellar must be 10 feet deep, do you mean the floor or the sealing?

Hi, Arne- The page doesn’t

Hi, Arne- The page doesn’t say that the root cellar must be 10 feet deep, it says complete temperature stability should reach about 10 feet deep.

Root cellar

I live in the desert were during the hottest time of year is around 118 deg. And even through out the night dose not go below 100 deg.. I need to know how deep I need to dig. What depth should the ceiling be, and how deep to the floor? Thank you

Found a root cellar

Hi! Looking for best advice/practice. I am very uneducated about a root cellars purpose. I had to google what a root cellar is and I'm curious about the process. I recently moved into a historic 1920's home and discovered a root cellar under the shed outside. I opened the door (hidden underneath a rug) and found standing water (no idea how much) and tons of mosquitos. There's not a ladder and honestly, looks kinda *scary*. Is it salvageable (assuming bc standing water there is not drainage). Should I drain it? What health risks are there if there's been standing water for who knows how long? Should I just pretend it isn't there? TIA for any feedback, thoughts and opinions.

The two most important

The two most important factors are to keep moisture out and have good air ventilation. Read the information on this page and scan some of the question and answers on this page. It sounds like your old root cellar needs some major work to function properly.

That sounds really creepy and

That sounds really creepy and cool!

Root cellar under Home

Good afternoon everyone, we are getting ready to build a straw-bale house and would like to put a root cellar in some what under the house. The entrance would be implemented into the island in the dining room, roll island out of way, go down the stairs into the root cellar. It would also serve as a storm shelter.

Here is what I am thinking , dig a hole to where the floor would be about 12 feet under ground, 8 feet of head room 6" thick reinforced cement roof/ceiling with 3' 6" of earth on top of that. The root cellar would not be directly under the house, just partial. please give me your 2 cents.. pros, cons, it does not matter, I want to do it right. Our land is flat, we have no hills this is why I am going with under ground.

So why isn't an adapted

So why isn't an adapted refrigerator or freezer going to work as a cool place for storing root vegetables? Lack of circulation or too much humidity? Would a wine cooler work for root vegetables?

Fridge

A loss of power would be quite a heartache

I only need to keep 15-20# of

I only need to keep 15-20# of potatoes and around 10#carrots. I was hoping there was a way to build a makeshift cellar by buring a plastic bin in the ground Now that I've read all these comments, sounds like that would not work. Is this correct?

Hi, Michelle: This really

Hi, Michelle: This really depends on the ground temperatures and conditions where you are. Even a homemade bin-type root cellar needs air circulation and protection from moisture, not to mention being far enough down to be in a consistently cool temperature. Even though every dime counts, the stakes here are rather small, so it might be worth experimenting, remembering that ground moisture and pressure are very vicarious things. Good luck!

does anybody know if a root

does anybody know if a root cellar can be used as a wine cellar? 50-55 degrees is the Ideal temp.

yes the root cellar is

yes the root cellar is perfect

Depending on where you are,

Depending on where you are, and I am in NY, you can also place a small hose/tube through the foundation or through a window or snaked up somehow to the outside. Cold air will sink and you can easily bring cold air in through a small opening, closing it off when the area is cool enough and opening it for a while to bring the temp. down slowly. Whatever your cold temp is outside, if it is below your indoor temp, you can get your room colder. I have a small root cellar in my old farmhouse in one corner of my basement. I am working on it to get it better insulated this winter, but it averaged around 50 all winter last winter with doing nothing but keeping it closed off. Half of my basement is a finished room that stays over 60 and up to 70, and I was still able to keep this small room in the opposite corner very cool. It can be done. And remember, in the summer you DON'T NEED it to be cold.You should be eating fresh from the farm at that point and should not need root cellar storage! And in the summer my basement is around 55-60 even when it is 80-90 outside for weeks on end.

I have not seen anything

I have not seen anything posted on this yet but does anyone know if one can use the space beneath stairs that go from garage to basement. I live in Central Wisconsin near the mighty Mississippi and was hoping I could insulate that area and vent it to make a good storage space. Any ideas appreciated. Also is there a shorter name or term for "the stairs that go from garage to basement". Concrete on 3 sides and 10 feet deep.

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