Root Cellars 101 – How to Build & Use One Successfully
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A root cellar is one of the simplest and most reliable ways to keep food cool without electricity. Long before modern refrigeration, families used natural cooling to store local food through long winters. I don’t know about your area, but we’ve had a lot more power outages in recent years. It makes me appreciate this storage option even more.
When properly designed, a root cellar maintains the right balance of temperature and humidity. This helps to slow microbial growth, reduce food spoilage, and keep produce fresh for months.
Whether you want to build a root cellar from scratch or improve an existing storage area, we can help you out. This guide covers everything from vent pipe placement to the best crops to store to ways to save money on your build.
The images in this article are from our root cellar, which is under our front porch. It’s accessible from the basement, but sits outside the envelop of the home. We use it to store vegetables, home canned goods, wine, and more.
Table of Contents
What is a Root Cellar?
A traditional root cellar is an underground storage space for vegetables and fruits. They sometimes include storage for canned goods or other foods. Root cellars take advantage of cool, moist underground conditions to store food without electricity.
5 “Must Haves” for Building a Root Cellar
There are five major elements that a root cellar requires:
- Ventilation: Some fruits and vegetables give off ethylene gas, which can cause other produce to spoil. Also, a tightly sealed cellar increases mold risk. Make sure fresh air can get in, stale air can get out, and air can circulate around the produce.
- Earth-shelter: Soil insulates and maintains a cooler temperature. A packed earth floor or gravel floor is better than concrete for keeping moisture (humidity) levels higher. Avoid tree roots.
- Humidity: A high humidity level of 80-95% keeps produce from drying out. This may cause canning jar lids to rust, so be sure to check lids and rotate stock if you store canned goods in the root cellar. Build in well-drained soil, and avoid flood prone areas.
- Darkness: Light can trigger sprouting, so if you have a window in your root cellar, keep it covered, and don’t leave the lights on.
- Shelving/Storage bins: Wood shelving and bins are naturally antibacterial. Wood also conducts heat more slowly than metal, and doesn’t rust. Avoid treated wood, and stick to those that are naturally rot resistant.
How much does it cost to build a root cellar?
The cost of building a root cellar varies widely. If you build a underground sandbag root cellar or remodel a basement corner yourself, it can be as little as $500. Most will cost $2500+.
If you’re looking for the cheapest option, remodeling existing space is usually the least expensive. Doing most or all of your own labor also keeps costs down.
You can reduce the cost by considering the space as both a safe room (storm shelter) and a root cellar. That might get you some funding from FEMA or state programs. See more in our related article: Safe Rooms Checklist. This applies to new home construction and retrofits.
10 Tips for Root Cellar Fruit and Vegetable Storage
Key storage tips to remember:
- Late-maturing crops store better than early maturing crops. Specific varieties also store better than others, and produce from healthier plants last longer.
- Check fruit and vegetable condition at storage time. If you note any damage on produce, use those items first. Regularly inspect produce during storage, too.
- Cure the vegetables that need it before storage. Vegetables that require curing include onions, garlic, winter squash, sweet potatoes, and potatoes.
- Wipe excess dirt off of root vegetables and store them in lightly dampened leaves or straw. Use fresh leaves each year to prevent potential pathogen buildup. Fresh sand and sawdust will also work, but are messier.
- It’s okay to wash produce, but make sure dry up excess moisture (and cure if needed) before storage to avoid rot.
- Less-than-ideal conditions shorten storage life. Try to get as close as possible to target temps and moisture levels. Use different areas of your storage for crops that are a best fit, such as storing carrots lower (colder) and winter squash higher (warmer).
- Store fruits that give off ethylene gas away from those easily spoiled by ethylene gas. You can also wrap fruit that produces excess ethylene in newspaper to contain the gas.
- Oher fruits and vegetable may absorb odors from strong smelling vegetables, like turnips and cabbage. Store them away from other food and where the odor cannot waft into the house.
- Do not allow fruits and vegetables to freeze. They will get mushy and rot.
- Track temperature and humidity to measure your root cellar performance. Keep the door closed as much as possible to keep the cool moist are inside. Letting heat in or very cold dry air in will reduce the storage life of your fruits and vegetables.
A Quick Guide: Fruit and Vegetable Storage Chart
This chart gives preferred temperature and moisture ranges for root cellar storage of a variety of fruits and vegetables. Adapted from the University of Missouri Extension Office.
Click HERE or on image below to download Printable PDF version of Root Cellar Storage Requirements.
See also:
How to Store Potatoes Long Term
Types of Root Cellars and Natural Cold Storage Options
Natural cold storage options include (click on any item in the list to jump to more information below):
- Basement or Under Porch Root Cellar – accessible from inside the home
- Traditional Root Cellar – buried below ground, accessible from outside
- Earth Berm – at ground level or partially above ground
- Above Ground Root Cellar – bermed, spring cooled or other above ground root cellars
- Barrel in the ground
You can’t build an underground root cellar if the water table is too high, or soil is too shallow.
How to Build a Root Cellar in the South
Root cellars don’t work as well in warmer climates, because the ground isn’t as cool. In the Above Ground Root Cellar article, my friend Paula shares her southern food production and storage tips. Southern gardeners have the advantage of being able to grow food year round.
The article “Build Your Own Walk In Cooler with a CoolBot Controller and A/C Unit” shares how to build low cost cold storage.
Retrofitting a Root Cellar in an Existing Home
The easiest option for building a root cellar is to section off a part of the basement for your fruit and vegetable storage. Old dirt floor basements without heat are great for maintaining proper temperature and humidity levels. (Make sure to insulate between the house and root cellar.)
Select an area with an existing window if possible, and use the window for ventilation. Fill the window with exterior grade plywood, and cut the necessary vent holes through the plywood. The plywood also blocks direct light.
North facing corners work well. They allow you to leave two exterior walls uninsulated, and only insulate the interior walls and ceiling. A north facing wall won’t gain heat from the sun. Use materials that tolerate moisture exposure.
Insulating between the house and root cellar is necessary so you don’t heat the root cellar from above. You also avoid losing house heat into the root cellar.
Your basement root cellar should have no standard heating or cooling. Insulate any ductwork or piping that runs through the ceiling above your root cellar (if any). Make sure vents or hot water pipes are well insulated so they don’t bleed heat into your root cellar.
Add a Root Cellar to a New Home
Many new homes have a small concrete exterior porch. Typically this area has 4ft footings and dirt backfill. You need to put a foundation wall under it anyway, so why not put this area to good use?
To convert this to a root cellar, have the builder put in full footings. Add an insulated exterior grade access door from the basement and two 4 inch vent holes. Add concrete slab on top as normal, and a light inside so you can inspect your storage.
Insulate the walls in contact with the basement, but do not insulate the outside walls exposed to soil. You want to maintain heat transfer between the soil and the root cellar.
Our porch root cellar measures about 6’x8′. It provides plenty of room for our stash of root veggies, plus gives a nice sized porch above. Because the root cellar is outside the footprint of the home, it maintains cooler temperatures more easily.
Building a Root Cellar Outside the Home
For an exterior root cellar, similar rules apply – have good ventilation, keep it earth sheltered and dark. Use a north facing door if possible, to avoid sun beating in and heating your cellar up.
Try for at least one to two feet of soil covering the root cellar. The more soil there is insulating the root cellar, the closer you get to ground temperature.
You may be able to repurpose a new septic tank or large pre-cast culvert. There are some root cellar kits on the market, such as these precast kits.
Whatever you build, use rot resistant materials that can stand the weight of wet soil. Don’t use shipping containers. They are not built to withstand weight on their sides.
Traditional Root Cellar
This is what most of us think of when we hear the phrase “root cellar”. There are insulated doors that lead down into the earth. These cellars go down or into the side of a hill.
Walls are concrete, cinder block, or more creative materials like old tires. You need to make sure the roof and walls are well supported to avoid collapse. Engage an architect or engineer to ensure your safety.
Earth Berm Root Cellar
Above ground root cellars are usually partly sunken with earth mounded on 3 sides and the door avoiding the direct sun. See the Above Ground Root Cellars post for more information.
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Barrel in the ground for (Zones 6-9)
This is a winter storage option. The size and depth depends on the zone you live in. (For more information on zones see: Plant Hardiness Zones & Microclimate.)
Take a large container, with holes drilled in the bottom and top. Bury it level with the soil with a bale of hay as an insulating cover. This will work into zone 7 and possibly into zone 6 depending on cover and conditions.
Barrel in the ground for (Zones 3-6)
Buy one 55gal large heavy duty garbage can, and a 32gal smaller garbage can that fits inside the larger one. Both the larger garbage can and the smaller one need holes in the bottom.
The inside can needs a cover with vents / screen. Cover exterior holes with screens to keep rodents out. It also needs significant insulation above it (over it). Bales of hay, or piles of leaves can insulate it.
Prepare a hole that is deeper than the large garbage can, with rocks and gravel in the bottom to create a simple French drain. Another trick is to dig a very deep, large hole next to the garbage can hole and fill that hole with rocks. The deeper hole acts as a drain for your shallower garbage can root cellar.
Once you have the large garbage can in the ground and secure, lower the smaller one into the larger barrel. Store food in the small barrel.
When you need access, grab from the top or pull out the smaller barrel. This makes it easier to reach food the bottom. There are many variations on this type of in ground storage.
How to Optimize your Root Cellar
To help you get started, we’ll “dig a little deeper” into our root cellar components. These are the keys to successful fruit and vegetable storage.
Root Cellar Temperature
Ideally, we want our root cellar temperature to be similar to refrigerator temperature, around 40 °F (4.4°C). In practice, the temperature varies by location, season, and other factors. Cooler is usually better, as long as it stays above freezing.
The temperature of the soil at 4ft deep is fairly stable. But that temperature varies with latitude and location. Any running underground water will also affect soil temps. The hydrology map will give you an estimated soil temp.
In extreme cold conditions, it’s possible for parts of a root cellar to freeze. The biggest risk is near the vents or exterior door. If you are expecting a short blast of extreme cold, move food storage away from the vents and door. You may even want to plug the vents temporarily.
This shouldn’t be a concern until temperatures drop below zero, or there are high winds driving cold air into the vents.
This soil temp database will likely be more accurate. Your root cellar is likely to be slightly warmer than either estimate, on average. Winter will be cooler than summer, which is what makes them useful for storage crops.
Root Cellar Ventilation
Improper ventilation is one of most common mistakes that people make when designing/installing a root cellar. They build their underground food storage airtight to keep things nice and cold, and everything spoils.
We need ventilation because some foods give off ethylene gas, which speeds ripening (and rotting). A root cellar that is too airtight may also build up excess humidity, leading to mold and mildew.
How should you ventilate your root cellar? Use two vents, about 3-4 inches in diameter. Place the vents so that one is near the top of the root cellar to exhaust stale air and ethylene gas. Run the other vent down to near the floor, to drop in fresh air.
Ideally, these vents are on opposite walls to improve air flow, but ours are next to each other and work reasonably well.
Four inch PVC vent pipes should be adequate for to up to around an 6ft by 8ft room. A larger room like a 8ft by 10ft should have even larger vent pipes or more of them. Make sure to put mesh screen on the outside of the vent pipe to keep mice and other small animals out. Angle or curve vent pipes so rain, snow or debris can’t fall into your root cellar.
How to Prevent Ethylene Gas Spoilage
When fruits such as apples and pears ripen, they give off ethylene gas. Ethylene gas decreases the storage life of some produce. Ethylene gas can cause sprouting, decay, mold, yellowing, shrinking, toughness, softness, bitterness and other damage.
To combat spoilage from ethylene gas, segregate the excess gas producers from crops that get damaged by the gas. Keep your fruits and mushrooms away from your greens and root vegetables. This is a good idea for your refrigerator produce bins, too.
Because our root cellar is fairly small, we usually keep our fruit in the insulated garage or front porch. Storage varieties hold for months in cool conditions.
Root Cellar Lighting
Light exposure is the enemy of food storage. Every time I see people lining up their canning jars or spices on open shelves, I cringe. It looks beautiful, but light bleaches out the color and the nutrient value of foods.
In the root cellar, light exposure may lead to sprouting and green potatoes. If you’re venting through a window, cover the rest of the window. If you have a light in your root cellar so you can see your food storage better, don’t leave the light on when you’re not using it.
A hunk of burlap drawn over bins of potatoes or fruit will allow ventilation while still blocking the light. A single high lumen incandescent or LED light should provide adequate lighting (unless your room is really huge). If for some reason your storage gets too cold, you can use an incandescent light to introduce a little heat.
Monitoring Humidity and Temperature
A high humidity level of 80-95% keeps produce from drying out. The soil provides some humidity.
Keeping track of temperature and humidity is important. You can track humidity with a hygrometer, and temperature with a thermometer like a Digital Hygrometer Indoor Thermometer.
Electronic monitoring is an option if you want more precise records. The Govee Thermometer & Hygrometer has a simple display and can sync via Bluetooth.
Keep Things Moist But Not Wet
Checking the fruit and vegetable storage chart, you’ll see that most store best with fairly high humidity. If you have a dirt or gravel floor in your root cellar, you’re in luck. Natural ground moisture helps to regulate humidity.
If you notice that your produce is shriveling, your root cellar is probably too dry. Take a tip from the grocery stores, and try a little misting action with a spray bottle. Avoid standing water, as that can lead to potential mold growth.
In dry environments, a shallow pan, a tray, or a shallow bucket of water can increase humidity. Be careful with this option, as it can attract pests or result in bacteria or mold growth.
Ideal Root Cellar Shelving
Shelving should allow airflow and add storage area. Keep a gap between the shelving or storage bins and wall to encourage air flow. Keep produce that likes cooler temps lower and food that like warmer temps higher.
Recommended Root Cellar Books
The classic root cellar guide is the book Root Cellaring: Natural Cold Storage of Fruits & Vegetables by Mike and Nancy Bubel.
The book contains detailed explanations of no electricity vegetable and fruits storage with specific temperature and humidity recommendations for each variety. There are also good photos and diagrams, which I really like.
The Complete Root Cellar Book is more recently published, and also received good reviews. Recipes from the Root Cellar helps you use your storage crops in the kitchen.
Related Articles
- Long Shelf Life Foods – What Lasts Best (with Chart)
- Preparedness Storage – Finding Room and Keeping it Safe and Sound
- Home Food Preservation – 11 Ways to Preserve Food at Home
This article is written by Laurie Neverman. Laurie and her family have 35 acres in northeast Wisconsin where they grow a food forest and annual gardens. Along with her passion for growing nutrient dense food, she also enjoys ancient history, adorable ducks, and lifelong learning.
Originally posted in 2010, last updated in 2026.
I put front porch on my parents house, The walls are block 9′ tall and the floor is concrete. The ceiling of the root cellar is metal decking with concrete poured on top to make the floor of the porch above. The exterior is about 2′ out of the ground. I have an insulated exterior door going into the basement of the house. I haven’t vented it yet because I wasn’t sure what i needed to do. It gets alot of condensation on the metal decking on the ceiling year round. Your post says 2″ pipe one high, and one low. With my foundation only sticking 2′ out of ground should i run one pipe as high as i can get it and other pipe down about 18″ so it’s not too close to the ground? Or should i run an elbow and pipe down the wall for the lower pipe so it’s closer to the ground?
thanks
The wall penetrations of our root cellar are at the same height. What’s different is that one of the penetrations is connected to an elbow with a tube that goes down to near floor level inside the cellar itself, and one is a straight shot in near the ceiling of the cellar. Does that make sense?
I talked it over with my husband, and we both agree that if you have the option 2 1/2 to 3 inches might be a better size for the ventilation pipes.
Yeah this makes sense. I didn’t put the size of the room in there but it’s around 8×12. I will put the vents in and try it. do you cap the intake off when it’s hot out? I live in central PA so our summers are pretty hot. Also do you think i will have trouble with freezing in the winter? It gets down around 0 plus the wind chill in the winter?
I have never had freezing issues here in Wisconsin where it is much colder, although my vents are 2 inch diameter. (I still don’t think you would freeze with larger vents. I keep it open in summer just to avoid stagnant, musty air building up. I haven’t work with them in a warmer climate such as PA, so you might need to experiment and see what works for you.
you can use a central plastic pipe to the outside with a vent cap to keep bugs out, run it in and turn down with a elbo go almost all the way to floor. Do this on each end of room. on outside put a foundation vent in center of room above ground,,,use the holes in the block and go down into the room. cut out the block and use the holes to vent through. the foundation vent should be one that will close automatically in very cold weather. my root cellar is 20 ft long and 8 ft wide. it is under a outside porch with concrete, we insulated under the concrete and put treated plywood under it to protect the insulation. works very well as we made 3 ft wide 8 ft long frames with rat wire stapled to the bottom, set it on 8 in blocks and went all the way down the 20 ft side and across 8 ft end. we store 20+ bushels of potatoes in this been with shelves above on all sides. a solid wood door opens from basement into this. Use 3 lights on ceiling with switch on outside of cellar, we have used the left over potatoes for seed for 5 years now. also store seeds for green house here also..with out venting we had a bad mold problem,,,after installing vents mold went away in a few weeks. good luck with yours
Thanks for sharing your experience.
This is great for your location. However I live in the low country of South Carolina. We have excessive ground water. It is only cool from late October to early March.
Any suggestions?
The post “Above Ground Root Cellars” may give you some ideas.
What do you know about options for root cellars in the south? We don’t have basements because of the water table and my house sits on a slab on the ground, so there is no crawl space. What are my options? I’d love to learn more about this!
Angel – I don’t have any experience with southern conditions and I haven’t been able to find a good resource on the subject (if one exists). You want to use physics in your favor. Even with high heat and humidity, the ground stays somewhat cooler. Possibly not cool enough that you could have a full blown root cellar, but maybe enough to buy you some storage time. If you could build a storage area that was earth sheltered or very well insulated, even above ground, but with a floor that was gravel (not insulated), that storage area should stay cooler. Think old-fashioned spring house, where they had thick walls and a stream running through the floor. You also want to make sure to include ventilation that draws from bottom to top to carry away ethylene gas, which promotes spoilage. It might make sense to have your intake run below ground level (if you can, or have it run through a mound of dirt) to cool the air before it enters, and vent near the top to pull off the warmest air. I haven’t tried anything like this because of where I live, but that’s the direction I would take. Good luck!
Thanks so much, this helps my research!
Rather than a root cellar, you may have to do more than one planting but in smaller batches. In the south, you have the advantage of an extended growing season which would make storage a non-issue.
Thanks! Our winters can be rough, but there are some advantages to living in the upper Midwest.
What a great root cellar…and your photos are awesome…a great list as well. Unfortunately, living on the west coast, root cellars are not common…wish I had one…but too much rain.
Have a great week.
What a fantastic & informative post! I'll be bookmarking it for future use! We'd love to add a root cellar, but first we need to regulate our food production and grow enough to make it worth the while 🙂 (Our potatoes were gone before the month we harvested in was out.) But I would definitely love to store more food rather than canning and freezing so much. Thanks!
How cold is "very cold"? Are we talking permafrost? The ground temperature stays relatively constant, no matter what the air temperature. Here's an example: http://www.duanesworld.net/duanesworld.net.sensors.htm
An insulated area above ground will buy you extra time in storage, too, especially in cold climate areas. We keep apples in the garage until it gets well below freezing outside.
You should see if you can find the root cellar book at your local library (If you don't care to buy a copy). They include a lot of different options for storage with minimal energy inputs, above and beyond what we normally think of as "root cellar".
My dream is a root cellar. But alas we live in a very cold climate and the cellar would need to be very deep and then we will have water issues. There is no sloped land on our small lot, and the water table is high. Any ideas?
Every decision has its good and bad side. My husband and I are debating moving, too. We love our home and our neighbors, but it's really tough being apart during the week (he works in a nearby city two hours away). There are no easy answers, especially in these economically uncertain times.
The root cellar was one of the best and easiest things we included in the house. I love it!
Another useful post Laurie. We have been teetering on whether or not to stay in our (suburban) home and build a root cellar, add solar or wind backup, or move out to a more remote location that already has these things and a plentiful supply of water, but you make a cellar look so good and easy… Making decision tougher. lol.
Ideally separate rooms would be preferred, and since you're building new you may be able to put in a partition at minimal cost, but the ventilation is the biggest factor. If you've got a way to get that gas out you should be okay.
Happy Mother's Day to you, too, and thanks for stopping by!
Thanks for clarifying about the fruits and veggies – that makes sense. I got my book back from my friend and thumbed through it and had seen a plan with a separate room but didn't get to read about it so I began to think it might be necessary to have two areas, but I'm glad to know that separate bins and good ventilation is all that is necessary. If I put the cultures out there, they will be sealed with lids – I'll do the actually "culturing" in the house, but would like to store them out there once they are done.
Thanks for all the help on the root cellar! Happy Mother's Day!!
Amy – I'd say yes to fruit and veggies in the same cellar, just not in the same bins, especially if you ventilate properly. You've got the book, so you've got detailed recommendations for the type of cellar you're looking at building.
If you hit the temperature range you're looking for, keeping cultures in there should be no problem. Before electricity, a spring house was often the preferred option, but I'm sure folks made due with whatever they had available. The only way to know for sure will be to try it. Mine tends to stay a bit warmer than ideal, so I haven't tried it. Also, there will be an assortment of microbes associated with the food in storage, so they may influence the composition of your cultures.
I do keep cultured veggies (my sauerkraut) in small (1 gallon) crocks in my canning pantry. I bring up one crock at a time, put a quart of it in the fridge and the rest in the freezer (to keep it live but dormant). I've still got kraut packed in good condition from last fall. (Which reminds me, I need to bring up another crock this week.)
Laurie, this is so good. I'm trying to be patient as it will probably be at least a year before we can afford to build the root cellar which will go into the side of the mountain behind our house. I'm wondering, can you section off a small area with a wall and put in extra ventilation so as to do fruits such as apples in the same root cellar? I'm also thinking that I could keep some of my dairy cultures in there – especially if the electricity were to go out. What do you think?
hmmmm…very different environment. I imagine heat and moisture are the biggest problems. If you figure something out, please let me know. Your growing season goes pretty much year round, no? So even if you were only able to keep foods a bit cooler using earth sheltering it would probably help. Thanks for stopping by. 🙂
Awesome post! I have been researching this very subject lately. I live in Florida though and have very few Root Cellar options. 🙁 Great post!
Hi Carol. Thanks for stopping by. I haven't been on THL too much lately – just too far behind in everything! I hpe you had a successful gardening season.
Hi Laurie, I found you on Homeschool Lounge. I’ve started a garden blog, too.
The red and white buckets have leaves in them, packed around layers of carrots and beets. I have also tried packing carrots in sawdust and sand, but have found leaves to be the cleanest option (very simple to brush off the root) and they also hold enough moisture (but not too much) so the carrots stay hydrated but don't rot.
Because we don't go through a huge amount of potatoes, I lay those out in trays on the shelves along with the onions and garlic. I keep the potatoes as low as possible because they prefer cooler temps. Last fall all shelves and half the floor space was full (this photo is from an earlier season – 2007, I think).
leave the green tops on the carrots and layer them in dry straw,not hay,but straw, they stay nice and clean and no mold like you might get with leaves.
Every time I’ve tried storing carrots with tops, they’ve wilted, badly, in a day or two.
What are in the red and white buckets?