root cellars in southern climes

I have been seeking ways to decrease our need for refrigeration. I live in zone 7b, with hot summers and frequently mild winters. Consequently, I store a lot of stuff in the fridge that really doesn't need to be there. The first alternative that comes to mind is a root cellar. However, I've been told that root cellars don't really get cold enough in the southern US to be effective. Building one would be a huge undertaking, so I'm turning to the experience of others. Does anyone in a warm climate have a root cellar? How well does it work for you? Suggestions? Advice?

There is a more stable temperature underground, that starts to get close to the annual average temperature in your area. For example, in my region it is well known that at 3 feet below the surface of the ground, it will not go below freezing so pipes are safe, but it will be nice and cold all winter, so buried potatoes and carrots are safe at that depth. I think in my region I was told that at 12 or 15 feet below the surface, the ground stays a very stable temperature around the year. We are approximately zone 5.

I hope somebody else gives a useful link, but I'm sure there's a website where you can find out the underground temperatures for your region.

I do suspect that a root cellar won't give you enough cooling, especially in summer, but I really don't know for sure. Do you have ground water piped into the house? I guess that should be at the deep ground temperature, and if it is cold enough, maybe you can somehow use it for cooling food.

Rebecca, you've given me something to research. It appears ground water temperatures correlate to soil temps, and that's mostly what I'm finding. This page page at Build It Solar discusses soil temp for geothermal systems. The first map is for mean earth temperature which, if I'm understanding this correctly, is below 30 feet under the surface. For my area, that's in the mid-60s F. Compared to a refrigerator that is no where near enough, but for things that can't be refrigerated--maybe? Most root crops I can overwinter in the ground, but that might be adequate for storing sweet potatoes and winter squash.

In some ways it's relative. The only other non-refrigerated storage I have is my pantry. It runs in the 80s in the heat of summer, so anything cooler than that would be an improvement!

I often find myself wondering how folks in the southeastern US kept and preserved food before refrigeration.

Leigh,

We are in a similar climate. I looked at the logistics of a root cellar and found that historically they were not used here, and tried to figure out why. The best answer I could come up with was that the winter temps here you can leave most root crops in the ground, as they are below the frost line. I have a few test beds I have left parsnips, carrots and beets in the ground, and they seem to be fine (but this has been a very mild winter). Potatoes have been a failure. Squash seems to be OK unless it's prolonged below freezing as long as it is dry (its the freeze thaw cylcle that seems to get them).

It just doesn't make a lot of sense to me to make a root cellar given that for winter storage. For summer storage the locals pickled meats (like country ham) but mostly you can eat fresh about 9 months a year. I have fava beans and onions going all winter here (not growing much but will pop up in spring) and thats what people did- they had season extending plants like collards rather than a lot of storage. My biggest storage item is definitely squash, and I am setting up shelves in the barn with a little bit of loose insulation but decent airflow.

The biggest problem with this style is I do get some wire worms, but I move stuff around and the chickens are pretty good at finding them.

I gave up on the root cellar when I realized what kind of drainage pain it would be with the high water table in spring most years and predominant clay soil.

In many areas, the spring house was the critical infrastructure, especially for dairy. It only takes a trickle of a cold spring to keep a cooler sized container cold.  I am toying with the idea for a spring fed cool box, basically an insulated chest freezer with an inner box to hold the produce.  My springs are about 60 in the heat of the summer so it is a huge improvement over ambient.  I don't think I have enough flow to cool a whole room, though, or I would LOVE a walk in cooler.  It is possible to combine technologies, like the spring water plus a coolbot to deal with peak loads.

Tj Jefferson wrote:Leigh,

We are in a similar climate. I looked at the logistics of a root cellar and found that historically they were not used here, and tried to figure out why. The best answer I could come up with was that the winter temps here you can leave most root crops in the ground, as they are below the frost line.

Tj, that's the kind of information I am looking for.

My experience echos what you say about leaving root crops in the ground. I have found that I can leave carrots, turnips, Jerusalem artichokes, parsnips, beets, radishes, and mangles in the ground and harvest all winter. A good mulch layer of leaves (could be straw) helps. It's never cold long enough for the ground to freeze too solid to dig them up. Like you, no luck with potatoes overwintering nor sweet potatoes. I understand why collards are a southern winter staple; they are hardy! If it doesn't get too cold I can harvest kale, lettuce, and other greens all winter too. I always grow my multiplier onions and garlic in winter. I was pleased that you mentioned favas because I planted them last fall for the first time!

Because I have goats I have a lot of milk, but I've been experimenting with different kinds of cheeses that I can store without refrigeration. (No cheese cave either). The brined Mediterranean cheeses seem to do well, and I've taken to storing them in the pantry in olive oil. It still gets pretty warm in my pantry in summer, so I would wish for a cooler place for them. It would be nice to have a cooler place to store eggs too. In the fridge, they keep for months and months unwashed. On my kitchen counter in summer, they only keep for weeks before they start to fail the float test. Storage temperature makes a difference for longevity.

I understand why Southerners traditionally kept a family hog and ate a lot of pork, Less meat to deal with than a cow!

R Scott wrote:In many areas, the spring house was the critical infrastructure, especially for dairy. It only takes a trickle of a cold spring to keep a cooler sized container cold.  I am toying with the idea for a spring fed cool box, basically an insulated chest freezer with an inner box to hold the produce.  My springs are about 60 in the heat of the summer so it is a huge improvement over ambient.  I don't think I have enough flow to cool a whole room, though, or I would LOVE a walk in cooler.  It is possible to combine technologies, like the spring water plus a coolbot to deal with peak loads.

R Scott, having a spring would be absolutely ideal. Years ago I lived on an off-grid farm in Tennessee. They used an old chest freezer to pipe spring water through for storing milk. It worked very well.

 It still gets pretty warm in my pantry in summer, so I would wish for a cooler place for them. It would be nice to have a cooler place to store eggs too. In the fridge, they keep for months and months unwashed. On my kitchen counter in summer, they only keep for weeks before they start to fail the float test. Storage temperature makes a difference for longevity.

On eggs, we used hydrated lime on unwashed eggs in a tub last summer and it worked fine unrefrigerated for a few months, then we ran out of eggs and ate them. This is a technique few people seem to know. But that is a reasonable option in my opinion. Cheese and cured meat storage are very challenging and I haven't figured it out. I made a bunch of biltong last year and it molded after a few months. This year I am using sealed bags with silica packets (still not refrigerated). Time will tell but it works for dried tomato and dried mushrooms for > one year. The packets can be regenerated and I reuse the bags.

Cheese- in humid climates it seems they rely on wax based on my time in Europe. The wax can be reused and historically was. My bees better get after it, but now we don't have the time or schedule for dairy.

Overall we are eating mostly with the seasons, which means I'm pretty carnivorous in the winter with lots of winter squash and basically vegetarian in the summer with fish. The big winner here in winter is mushrooms- they have been bountiful and incredibly delicious. I am foraging hen of the woods right now and we have wild oysters all over the place. Just found some chicken of the woods but its a long way away and looking for closer colonies (but I stole the log to try to get it started here!)

I love this climate it has been wondrous. I'm from the western US and northern Europe and this is sooo much better.

Tj - we're trying the lime water egg preservation trick this year. So far I've filled one 15 litre bucket and have started on the next. The few that we've fished out have been fine, so fingers crossed this works well long term.

Tj Jefferson wrote:On eggs, we used hydrated lime on unwashed eggs in a tub last summer and it worked fine unrefrigerated for a few months.

I'm glad you mentioned liming eggs. Several years ago, I experimented with a number of techniques including dehydrating, water glassing, and liming them. The water glassing and liming were easiest, although water glass isn't so easy to find nowadays. Pickling lime is easier to come by. I found they kept for about four months before developing a metallic taste.

I rely on my freezer a lot for meat and some cheeses, also canning for meat. I'm in South Carolina and find dehydrating a challenge because of our humidity. As soon as anything comes out of the dehydrator and cools, it's already losing crispness.

Mediterranean cheeses such as feta, halloumi, and domiati are traditionally stored in brine, although they get too salty for my taste after a while. So I transfer them to the olive oil. I made four one-gallon crocks of EVOO stored cheese last summer and found they keep very well. We're enjoying them now. I was a little worried about quality because our pantry gets pretty warm, but they are fine.

I still rely on my fridge too, even for things like bread, which gets moldy after just a day in the bread box. I know there are a number of things that don't need refrigeration (ketchup, fermented foods, jams, and jellies, etc) but I keep them in the fridge for longevity's sake. Cooler storage conditions would certainly be helpful, although this discussion has helped point out that digging a root cellar would probably be more work than it's worth. I'd still like to figure out alternatives to refrigeration for cool food storage. Everyone's ideas help.

We have downsized our refrigerator for meat and dairy since they need 40F at least.    There are ceramic butter keepers that use water that work well.  Yogurt holds well in a root cellar temp of 50F-60F for a few days.  

We used to have a root cellar on the side of the hill, in the shade, that faced an almost constant wind.  The cold air would come in the bottom of it, and go out 2 vents in the top.  

Vegetables do well in a root cellar also because it's dark, and a pretty constant cool temperature.    

To me a root cellar isn't used to keep things cool/cold. It is actually used to keep things warm, that is not frozen outside up north where it turns into mush once it goes above freezing. People in the north use it to keep food not frozen, people in the sub-tropics/tropics don't really use it to preserve food. Traditionally things in the south were mostly salted/smoked/fermented or dehydrated.

To better help why exactly do you want to have a root cellar?
Store: Root Crops (they survive in the ground)
Store: Spices (they are normally dried&even powdered)
Store: Kale/Collared/Greens (they are better in the ground and overwinter will)
Store: Nut (dried, they keep at room temp for quite a few months in their shell)
Store: Beans (dried is the usual way to go, maybe even fermented then dried)
Store: Grains (dried, maybe even dried & powdered, turned into a alcohol soaked cake, or fermented to beer/etc)
Store: Fruits (dried, fermented, sugared-jam-syrup, soaked in alcohol)
Store: Mushroom (dried, fermented)
Store: Meat (salted-ferment, then smoked-dried)
Store: Eggs (just don't wash them and they last very long at room temperature)
Store: Dairy (ferment, then semi-dry to cheese, then store in oil or salt/lime water at room temp)

If you just want to have a storage room you can just build a room/barn/shed/basement and add 12inch of rigid foam insulation (r-60 for $4000) and you can probably cool the place with just a block of ice once a week.

S Bengi wrote:To me a root cellar isn't used to keep things cool/cold. It is actually used to keep things warm. . .

Well, it is all relative, isn't it? Good point!

To better help why exactly do you want to have a root cellar?

Your mention of room temperature can probably best illustrate that. For me, room temperature in summer is about 85 F, so the "normal" parameters and recommendations for room temp aren't useful. For example, I can keep unwashed eggs in the fridge for months, but at 85 degrees they only last for weeks before failing the float test. It's the same with fermentation. I left some kimchi out at room temperature this past summer as an experiment. It didn't take long before it became slimy and developed a horrible odor. I can keep it up to a year in the fridge.

Hence, my original question---would a root cellar in the un-air-conditioned South increase storage longevity for at least some foods? We've modified eating and preservation strategies for our region, but I'd still like to see if there isn't more I can do to decrease my dependency on refrigeration. I have a number of books on root cellaring, but they don't address my climate. I realize 40 F isn't realistic in my part of the country, so here I am, turning to others with similar experience.

I want to build a combined root cellar and cheese cave in zone 8b/9a. I'll make a thread about it on here once I've finished it, and might take some temperature readings through the year. My main reason is to age and store natural-rinded hard cheeses, but I'd also like somewhere to store potatoes and apples, and maybe some roots and ferments.

There are a few reasons I can think of to root cellar things even in this climate. Mice and other wildlife can be more active over winter and can eat things if they're left in garden beds, sometimes we might want to harvest a whole bed and sow it to a cover crop in autumn, and also sometimes it's nice to have winter to focus on stuff other than harvesting, and not have to go out in the cold and rain to dig up roots from boggy soil.

Kate Downham wrote:There are a few reasons I can think of to root cellar things even in this climate. Mice and other wildlife can be more active over winter and can eat things if they're left in garden beds, sometimes we might want to harvest a whole bed and sow it to a cover crop in autumn, and also sometimes it's nice to have winter to focus on stuff other than harvesting, and not have to go out in the cold and rain to dig up roots from boggy soil.

Kate, you've just breathed some life back into my root cellar dream lol. What you say about winter harvesting is so true. It's definitely no fun digging critter gnawed root crops in the cold rain and mud.

I so wish we had a basement. That would solve my dilemma. As it is, the question is the amount of work to dig a root cellar versus the benefit. I have to convince my husband that the benefit would outweigh the work.

I'm definitely looking forward to your upcoming root cellar / cheese cave thread.

Leigh Tate wrote:

I'm in South Carolina and find dehydrating a challenge because of our humidity. As soon as anything comes out of the dehydrator and cools, it's already losing crispness.

I'm much cooler than you, but the humidity issue during "drying" season is a major issue as our overnight dew is a main source of water for plants at certain times of the year. When I remove food from my dehydrator, I put it onto metal cake pans and put them in the fridge to cool for a good few hours. Then I remove the pans and pour the food into a glass jar with a metal lid (a canning funnel helps with this!). In a humid environment, plastic will not keep the humidity out. I will occasionally add a dehydrating packet as well, but usually that hasn't been necessary if the food is "fridge cool" when I jar it. For some things that I do in small quantities, I will put the food in small baggies, but then I put all the baggies in a glass jar.

I totally agree with the not digging half-chewed veggies in the winter. I also agree that there's a big difference in food storage when temps are in the 80's than here where the ocean cools everything at night even if it is hot during the day. I also agree that convenience is *everything*. So I'll back up the idea of needing to find a convenient way to lower the temperature of your stored food from the 80+ range to at least the 60-65 F range - there are lots of things "modern" people tend to store in the fridge that would be fine at 60-65 F, better at 55 F, but certainly don't require fridge temperature. Looking at that excellent link above, a cellar will need to start at 5 feet down and go deeper to do you much good. Would the terrain of your land allow you to dig into the side of a hill to help? If you do try to build something, I'd plant lots of shade in layers above it! Plant evapotranspiration has been shown to reduce temperatures more than non-living shade. Hmmm... combination root cellar and hugelculture? You could start a trend!

The other aspects no-one's mentioned are the natural water table height (winter or summer) and the flood risk. Both of those are moving targets with some of the weather-weirding that's happening, so if I was going to the trouble of building something, I'd chose to err on the pessimistic side so I wouldn't loose my food at exactly the time I might need it the most.

Have you looked at the double stoneware jar with wet sand between them trick being used in some hot countries? I don't know if they'd have the same effect in a humid environment, as I think they've been proposed for hot dry climates. That said, coupled with a deep cellar, it might give you a few more degrees.

It looks like people have covered a lot of ideas.  Here are a couple more.  First is one that I don't know if it would work in an area with high humidity - it's basically a huge, walk-in version of the "pot-in-a-pot" method described by Jay Angler just above.  It is not refrigeration, just a cooling chamber.  The directions and video are here: Access Agriculture Making a Cooling Chamber for Tomatoes

The way Access Agriculture is recommending it be used is to cool down a crop that was just picked in the hot sun, so that the crop will last to market.

Another possible option...you can make a cold-as-you-want-it refrigerator quite easily out of a chest freezer and it uses roughly half of the electricity of the freezer.  We have one set up and we just use a simple kegerator thermostat  - no wiring or drilling or modification necessary.  You can do it cheaper, I believe, if you are willing to play with wiring.  But we didn't want to permanently change that chest freezer.  

Here are directions and how it works at the New Life on a Homestead website How to convert a chest freezer into a refrigerator  Now there are way more devices available online for doing this... they start at about $29 on Amazon. Most are digital now.

I've found it incredibly convenient.  We have a very small regular upright refrigerator, and the 7 cu ft chest fridge is where we store our vegetables.  This allows us to store about two weeks worth for two people who eat mostly vegetables.  I was surprised that I find it easier to pull out and search for veggies in the chest fridge rather than a regular fridge.

Two things I learned about chest freezers... only a few brands will warranty their freezers in high temps, like up to 110F.  Be sure to read the warranty before buying!  And second, many Danby chest freezers have a 5 year warranty.  That seems to be the longest we found for a regular chest freezer.  Chest freezers I've had in the past tended to last a really long time anyways, but most have a 1 year warranty.

Another thing we discovered, not all chest freezers are caulked at the joints.  You definitely want to do this inside the compartment before using it.  My husband siliconed it very thoroughly. The reason is twofold - when used as a refrigerator, a chest freezer collects a lot of moisture that you have to wipe out periodically. (Unlike a refrigerator, there is no drainage setup because you are presumed to have everything frozen in there.)  You wouldn't want moisture to work into the walls of the freezer/fridge.  Second reason we found for making it watertight is just if you spilled something in it.

I made this post a couple years ago and we still love our chest fridge.

Jay Angler wrote:I'm much cooler than you, but the humidity issue during "drying" season is a major issue as our overnight dew is a main source of water for plants at certain times of the year. When I remove food from my dehydrator, I put it onto metal cake pans and put them in the fridge to cool for a good few hours. Then I remove the pans and pour the food into a glass jar with a metal lid (a canning funnel helps with this!). In a humid environment, plastic will not keep the humidity out. I will occasionally add a dehydrating packet as well, but usually that hasn't been necessary if the food is "fridge cool" when I jar it. For some things that I do in small quantities, I will put the food in small baggies, but then I put all the baggies in a glass jar.

Jay, I will definitely try this idea. I've taken to over-drying (if there is such a thing) items to rock hard, thinking the bit of moisture they pick up won't be enough to be a problem. Mostly, that works. After they're cool, I've been vacuum packing them in canning jars. That keeps things dry and also keeps out pantry moths! (another big problem for me)

I also agree that convenience is *everything*. So I'll back up the idea of needing to find a convenient way to lower the temperature of your stored food from the 80+ range to at least the 60-65 F range - there are lots of things "modern" people tend to store in the fridge that would be fine at 60-65 F, better at 55 F, but certainly don't require fridge temperature.

You're talking my language, lol. My goal is always to keep it simple.

Looking at that excellent link above, a cellar will need to start at 5 feet down and go deeper to do you much good. Would the terrain of your land allow you to dig into the side of a hill to help? If you do try to build something, I'd plant lots of shade in layers above it! Plant evapotranspiration has been shown to reduce temperatures more than non-living shade. Hmmm... combination root cellar and hugelculture? You could start a trend!

The other aspects no-one's mentioned are the natural water table height (winter or summer) and the flood risk. Both of those are moving targets with some of the weather-weirding that's happening, so if I was going to the trouble of building something, I'd chose to err on the pessimistic side so I wouldn't loose my food at exactly the time I might need it the most.

Lots of good ideas here. I'm in the northwest part of the state, so no worries about water table height. Our house is on a slope, so it's possible we could dig into a hill somewhat. Just not sure if it would be deep enough. My husband thought about digging out the crawlspace under the pantry.

Have you looked at the double stoneware jar with wet sand between them trick being used in some hot countries? I don't know if they'd have the same effect in a humid environment, as I think they've been proposed for hot dry climates. That said, coupled with a deep cellar, it might give you a few more degrees.

A Zeer pot. Yes, I have. Our humidity is too high, however, so the dampness in the sand was slow to evaporate and I couldn't get much of a temperature difference.

the root cellar that came with my place in tn is extremely humid at certain times of year and is full of mold and spider webs, I think it needs to be deeper in ground with water proof floor, but I'm no expert. only good aspect is it does not freeze in there even when 20 degrees outside.

Kim Goodwin wrote:It looks like people have covered a lot of ideas.  Here are a couple more.  First is one that I don't know if it would work in an area with high humidity - it's basically a huge, walk-in version of the "pot-in-a-pot" method described by Jay Angler just above.  It is not refrigeration, just a cooling chamber.  The directions and video are here: Access Agriculture Making a Cooling Chamber for Tomatoes

Very interesting. The video does make it seem like they are in a dry climate, though. I mentioned I couldn't get a Zeer pot-in-pot to cool much, so I'm guessing it would be the same with the cooling chamber.

Another possible option...you can make a cold-as-you-want-it refrigerator quite easily out of a chest freezer and it uses roughly half of the electricity of the freezer.  We have one set up and we just use a simple kegerator thermostat  - no wiring or drilling or modification necessary.  You can do it cheaper, I believe, if you are willing to play with wiring.  But we didn't want to permanently change that chest freezer.  
. . . .

I've found it incredibly convenient.  We have a very small regular upright refrigerator, and the 7 cu ft chest fridge is where we store our vegetables.  This allows us to store about two weeks worth for two people who eat mostly vegetables.  I was surprised that I find it easier to pull out and search for veggies in the chest fridge rather than a regular fridge.

YES! A chest fridge is one of the things I am planning to do! My current set-up is that I have a chest freezer and second fridge in my pantry. That doesn't help my situation because they produce heat. We're in the final steps of moving the freezer out to our enclosed back porch where we'll set it up on solar. We just have to finish the wiring and make sure the battery bank is fully charged. Then we can plug it into the inverter.

Then we'll add a small 5-cubic-foot freezer to convert to a chest fridge. My second pantry fridge is old and a real energy guzzler. I'll get rid of it.

The root cellar, then just seemed like the next step for intermediate temp storage for potatoes, winter squash, apples, sweet potatoes, etc. Also my crocks of olive oil stored cheeses. Jay's right in that there are so many things that don't need refrigeration. I'd love to get more things out of the fridge.

Even though I'm not a fan of plastic at all, it ended up solving a storage issue.  We found that plastic organizers keep mushrooms fresh way, way, way longer than anything else we tried.  Paper bags mold in a chest fridge...  I think the chest fridge holds moisture more than an upright one.  Oh, we also have a container of zeolite in there, to help absorb the gases that make plants mature/ripen/rot.  

Two things I learned about chest freezers... only a few brands will warranty their freezers in high temps, like up to 110F.  Be sure to read the warranty before buying!  And second, many Danby chest freezers have a 5 year warranty.  That seems to be the longest we found for a regular chest freezer.  Chest freezers I've had in the past tended to last a really long time anyways, but most have a 1 year warranty.

Lots of good tips here. Thanks!

bruce Fine wrote:the root cellar that came with my place in tn is extremely humid at certain times of year and is full of mold and spider webs, I think it needs to be deeper in ground with water proof floor, but I'm no expert. only good aspect is it does not freeze in there even when 20 degrees outside.

Hmm, The spiders and mold definitely don't sound good. But from what I understand, root cellars are supposed to have 90% humidity (?) Did your root cellar come with ventilation?

Kate Downham wrote:I want to build a combined root cellar and cheese cave in zone 8b/9a. I'll make a thread about it on here once I've finished it, and might take some temperature readings through the year. My main reason is to age and store natural-rinded hard cheeses, but I'd also like somewhere to store potatoes and apples, and maybe some roots and ferments.

There are a few reasons I can think of to root cellar things even in this climate. Mice and other wildlife can be more active over winter and can eat things if they're left in garden beds, sometimes we might want to harvest a whole bed and sow it to a cover crop in autumn, and also sometimes it's nice to have winter to focus on stuff other than harvesting, and not have to go out in the cold and rain to dig up roots from boggy soil.

In my limited experience trying to make a cache (a very simple root cellar), nothing will attract rodents better than a root cellar kind of setup, which is cozy and out of the weather. Protection from rodents would be very challenging in a root cellar- they will get in there. I have a cat that has access to the garage/barn, and since the cat moved in it has been fine, they tore up my dry seeds last year. If I could figure out how to make a root cellar with a kitty door it might help. We have voles and mice and squirrels and rabbits here as thieves. The rabbits seem to care very little for anything but carrot tops and wierdly they love love love shallot tops. Haven't been a big issue with anything else. Deer will eat the tops of parsnips carrots and onions here. Squirrels dig up my onions initially then havent been bad. Mice and voles don't seem to damage much left in the field (most of my "beds" are silvopasture rows maturing) The other ones haven't been a big issue this winter which is the first big planting I just left in the ground.

I would think a cave would be very useful for cheese and slow curing of meats as is traditional in warm mediterranean area. Mice probably won't bother those products. Cheese in my understanding is not prone to dangerous cultures.  I would think other product that already have an established culture like kimchi and maybe keifer or kombucha would store as well for a while. I would think fermented veggies would last as well, that is traditional in many parts of the world to bury ceramic pots in the ground.  

I get the idea about having a cooler area compared with the kitchen especially if you are using the kitchen in summer, but honestly we just eat fresh stuff all summer until we just want a frozen pizza to break up the monotony. In terms of storage I agree with S Benji that the traditional ways reflect that list based on my discussion with people who grew up out here before electricity. To my knowledge no one tried ice houses as most years there wasn't enough ice to make it viable. We had one of the coldest years on record last year and the lakes didnt freeze enough you could cut ice.

look at the design of root cellars from Sepp, he has a detailed diagram in his book with an intake pipe that is long and runs underground and slightly upward, allowing condensation to form and run back down. He has a small "chimney" to allow a draw through the cool pipe. Spiders are a given. My issue is that periodically the groundwater stays very high in clay soils and the humidity will be from that and not air. Unless you are building a boat, you are basically reliant on essentially a Mike Oehler underground structure with appropraite drainage, which is a lot of work for a storage area.  

When I was researching food storage temperature and longevity, I discovered that the food industry has a formula for this. Called the Q10 temperature coefficient, it's defined as the measure of the rate of change in a biological or chemical system for every 10°C (18°F) change in temperature.

Starting with a baseline of "room temperature" or 22°C (72°F):

For every 10°C (18°F) increase, shelf life is halved.

For every 10°C (18°F) decrease, shelf life is doubled.

You can see why storing even canned and dehydrated goods at cooler temperatures is important. My pantry averaged in the 80s°F last summer and reached 90° when the outdoor temps were over 100°F. This has been a motivator in trying to figure out better food storage conditions.

Our plan is to first get the freezer and extra fridge out of the pantry and set up on the back porch on their own solar power source. The next step will be to see what we can do to get the pantry cooler: better windows, window coverings, and insulation, etc. If we could manage to keep the pantry at room temperature, that would make me extremely happy.

The last step will be trying to figure out storage somewhere between room temp and refrigeration, for the many items that would be happiest in those conditions. That's where I'm thinking a root cellar might fit in.

I love that this discussion has included input from such a diversity of experiences and viewpoints. All of those really help me in trying to figure out what would be best for our situation because there is no one-size-fits-all solution to food storage.

Leigh Tate wrote:

Our plan is to first get the freezer and extra fridge out of the pantry and set up on the back porch on their own solar power source. The next step will be to see what we can do to get the pantry cooler: better windows, window coverings, and insulation, etc. If we could manage to keep the pantry at room temperature, that would make me extremely happy.

Many people don't make the connection that Fridges and Freezers are Heat Pumps! Their job is to pump heat from their insides to the air surrounding the outside. The hotter it is outside, the more that equipment has to work to do its job. Keeping the fridge and freezer in places that can be kept cool in the summer and where they won't heat up *other* food you're trying to keep cool, makes a heap of sense.

The problem is to try to adapt those mechanisms to the environment. When camping, I used to keep a wet towel over the cooler to use evaporative cooling to help conserve the ice. That doesn't do much good in a humid environment unless there's air flow to help out, and if the air one pushes into the area is hotter than the air already there, it's easy to get a "net sum gain" or sum such thing. (pun intended) One of those power consumption testers (we have a "kiloWatt" version) might be useful. For example, if you put a small fan to augment the air flow over the fridge coils, would the decrease in power consumption of the fridge over 24 hours be less than the increased over-all use of power when the power to run the fan was added in? In my ecosystem, 95% of the year the answer would be no. But in the summer when hubby needs to freeze his meat chickens all at once and the freezer doing the job is running 24 hours a day for several days, a box fan moving that warm air out of the barn makes a huge difference and is well worth the power needed to run the fan.

Leigh has stated that she also has plans to insulate the pantry better. Insulation slows down the transfer of heat, but it still requires attention paid to where and when the heat is from. Many traditional homes had windows set up so that there were low windows on the "summer breeze" side and high windows on the downwind side to get a chimney effect. In other words, insulation helps with status quo, but if the goal is to keep that room cooler than the surrounding area, having a way to let cooler night air in, then shut it up during the heat of the day to trap that cooler air as long as possible, would make sense to me. Alternatively, the room needs a "source of lower temperature mass". For example, if you had an uninsulated water tank in the pantry that then fed into the hot water heater, you'd get mild preheating of the water while cooling the pantry - but in a humid climate, it better be on a drained tray as it would have plenty of condensation on it! I'm amazed how much condensation our toilet tank gets if it gets flushed too often under certain climactic conditions.

Jay Angler wrote:Many people don't make the connection that Fridges and Freezers are Heat Pumps! Their job is to pump heat from their insides to the air surrounding the outside. The hotter it is outside, the more that equipment has to work to do its job. Keeping the fridge and freezer in places that can be kept cool in the summer and where they won't heat up *other* food you're trying to keep cool, makes a heap of sense. The problem is to try to adapt those mechanisms to the environment.

I confess it was only when we stopped using air conditioning that I realized how much heat the freezer and fridge were producing, which added to the conditions in the pantry.

Jay Angler wrote:Leigh has stated that she also has plans to insulate the pantry better. Insulation slows down the transfer of heat, but it still requires attention paid to where and when the heat is from.

I think about this a lot, and understand that better insulation will help, but that eventually the inside will rise to equalize temperature with the outside. Our daytime highs usually get into the 80sF around April and stay there until September. 90s to 100F is common for us in July and August.

One idea we're entertaining for the pantry is a "California" aka cool cupboard. This is basically a screened shaft with a cool air intake under the house and a hot air vent out the roof. They used to be used for food storage with wire shelves inside. Possibly, if we buried the air intake under the house we could conceivably draw in cooler air and maintain a better food storage temp in the pantry. There is one in Australia where the folks did this for their refrigerator, to carry the generated heat from the compressor out of the house. The link to photos and more information is here.

Jay, lots of good food for thought in your comment.

My husband has been researching this exact same thing as we live on the line of 7A & 7B. He has found this website. http://oklahomapreppersnetwork.blogspot.com/2009/11/root-cellar-part-1.html?m=1

The article Kerri linked to is a summary of this book,  "ROOT CELLARING" by Mike and Nancy Bubel, (Rodale Press). I read this book years ago and it is well worth reading if you want to set things up as well as possible.

With the increase of flood issues, the comment about how in warm climates fully buried is better, may no longer be the best option. I'm thinking that I would prefer to build it above ground earth bermed on all sides, but I'd like to put the door into an ante-room that could be used for other purposes and would insulate between the ante-room and the cold cellar.  However, that opinion is informed by my location and a sense of how high the water level can get in the winter and some of the weather weirding my area has experienced.

Many years ago I dug a root cellar in 6b.  I don’t remember the details, but, while it was cool, it was not a replacement for a refrigerator.   It did serve to keep root crops a little longer.

Hi Kerri,

Welcome to Permies!

“the root cellar that came with my place in tn is extremely humid at certain times of year and is full of mold and spider webs, I think it needs to be deeper in ground with water proof floor, but I'm no expert. only good aspect is it does not freeze in there even when 20 degrees outside.“

I’m in southern Tennessee and the humidity problem is what I’m worried about. Summer would fill my root cellar with mold and mildew. Winter temps might get down to 10F. Anyone else have experience with root cellar in the southern US? Can’t decide if I want to build one or not!

As a child in South Carolina in the 1950s dirt poor South, my Daddy would make a potato hill. He would dig down about a foot in the ground make a maybe 24 inch round hole foot deep, line it with straw, not a whole bale maybe 3 inches, then put a burlap bag over that, pile potatoes in hole on top of burlap mounting them until you had a good bushel of white or sweet potatoes. Then he made a teepee over this with short small tree limbs, covered those with a burlap bag or 2, then piled dirt, straw over it all. Made a mound of dirt covered taters. He would leave a small opening just big enough to get your hand into, but would cover it with a brick. We would go out to the tater hills beside the barn get potatoes white or sweet for our mama to cook, taters lasted all winter. You want at least a good foot of dirt covering the teepee.

Els Suggle wrote:As a child in South Carolina in the 1950s dirt poor South, my Daddy would make a potato hill. He would dig down about a foot in the ground make a maybe 24 inch round hole foot deep, line it with straw, not a whole bale maybe 3 inches, then put a burlap bag over that, pile potatoes in hole on top of burlap mounting them until you had a good bushel of white or sweet potatoes. Then he made a teepee over this with short small tree limbs, covered those with a burlap bag or 2, then piled dirt, straw over it all. Made a mound of dirt covered taters. He would leave a small opening just big enough to get your hand into, but would cover it with a brick. We would go out to the tater hills beside the barn get potatoes white or sweet for our mama to cook, taters lasted all winter. You want at least a good foot of dirt covering the teepee.

I am curious if people have tried this in Tennessee. I have heard that not harvesting your potatoes here does not work, and fear that this method might feed more critters than people.  Possibly hardware cloth might solve the latter issue.

Zone 9a, south central LA here 👋 my mom says that her people used to store root veggies under the cistern (rain collection barrel). They were usually about 3 feet off the ground but I’m wondering really how cool that would be. And How to keep critters out. Anybody heard this? My follow up question is: since we don’t have a sister, but our house is about 3 feet off the ground, could we store root veggies under there? Maybe in a metal container with good latches to keep the rats and raccoons out?

Hi Lilian,

Welcome to Permies.

I was reading this because I live in Coastal NC. I have wanted a root cellar for the longest time. I have trouble keeping produce fresh for very long. This is a hot and humid environment. Living at sea level seems to make building a root cellar impractical. When you dig down, you get water. I have looked for ways to store potatoes and other produce. I have experimented with boxes and bags kept indoors. I have attempted to research online how to create my own indoor root cellar conditions. But have not found that anyone has done this. I have researched ways to store produce as well. I really want my potatoes kept out of light and fresh. Also onions seem to go bad quickly. I realize that these need to be stored separately and do keep them separate. Any ideas? This is what limits me in growing these myself. How do I keep it fresh?

These are some of the things I would need to know:
1. How much land do you have to work with?
2. How regular is your rainfall?
3. Do you have a budget - can you throw money at the problem up front, so that you get long term food security/quality of life improvement?
4. You say you're at sea level, but sea level is a moving target. Will one bad storm flood your whole property? Are you actually on what should be considered "flood plain"?

I do *not* need to know your exact location - just general factors. However, I used to be quite sure my land was safe from major ocean flooding, and some recent evidence suggests that even if I am safe, my grandchildren may have to plan on being waterfront property, at least during big storms. I'm hoping it would be more like my great, great grandchildren, but our planet is not a static object. I'm in the way of the Cascadian Subduction, which has created much larger Tsunamis that people thought they did 30 years ago when we bought. I still feel the risk is low in my lifetime, but I'm doing my best to research what the risks and best practices are. I'm encouraging you to do the same for your area.

Minus buildings and concrete, my property is 18000 sq ft. I also live in a HOA so I have to comply with their requirements. I have a 1500 sq ft home, 12x10 shed and 24x24 garage/workshop. My elevation is 5 meters. I have multiple areas of standing water when it rains good and my ditch fills nearly to my yard level. Average monthly rain is 9 inches with most of it in September. I am also in a hurricane and tropical storm prone area. I was thinking that maybe I could use space in my garage or shed as a root cellar. I just don't seem very successful at creating the optimum environment. Humidity is very high in this area. I have trouble keeping the humidity levels down in and under my house. I have installed crawl space dehumidifier and a couple of blowers. I plan to install sump pump next and french drain. Then maybe do a rain garden in the area I pump to at the rear of my property. The garage and shed both sit on concrete slabs.

Potatoes: what months can you grow them and simply harvest and eat?

Onions: what months can you grow them and simply harvest and eat? Can you grow walking onions there and if so, for how many months. I get a great spring crop, less but still good enough fall crop, I have a few on my window ledge at the moment (beginning of March), and I do a *lot* of substituting the walking onion greens for cooking onions in just about everything.

Have you considered just getting a "fruit/vege fridge for the garage and running it on the warm side? Fridges help control humidity, but you might need 2 of them to keep potatoes and potato-friendly veg in one, and onions a bit warmer and with things that don't mind a bit of onion flavour taking over.

If you *don't* want to use as much power, I had wondered about putting cupboards around the north side of the largest rainwater catchment tank you can afford, to use it to moderate and cool the veggies. People used to put baskets down their wells with food in crocks to just above the water line, and the places that was done, the water was probably in the mid-50F much of the year. You'd have to catch rainwater in a bucket and measure its temp. Ours was much colder than 50F yesterday... I got hailed on! This approach was used by a farm I read about. It wasn't perfect, but it did extend their ability to store food without electricity, however I think their tank was quite large, and the HOA might not be into such things.

Greenhouse as Root Cellar/PotatoeHouse
An unheated greenhouse can give you an extra 10F+ pushing you up a zone or two. So that zone8 is now a zone 9B. You can now easily keep your potatoes/beets/carrot/ cabbage/kale/spinach/squash/etc in dirt and ready to be harvested. You can even grow them outside and then "transplant" them in the greenhouse with just enough dirt and space to keep them alive. If you stagger your planting time and cultivar you can have it where things in the greenhouse are ready at just the right time that you need them.

But back to a regular root cellar.

Cultivar Selection.
Even with the best root cellar setup with the perfect temp/airflow/humidity/etc, there can be a over a 3x difference in shelf-life based on just which cultivar of onion/poatoe/cabbage/etc is being stores/plantes.

Curing.
There is a critical hardening off process that is needed between getting the produce off the land and then storing it in the root cellar.

Yearly Temp'
The average yearly temp here in Boston is 52F. the coldest month is January with a mean temp of 30F. So with the thermal mass of the root cellar, it get the extra warmth in the winter to keep the produce cool but not frozen mush. in places like say Savannah, GA all the temps are about 20F higher so, everything in a perfectly built root cellar will go bad 4 times as fast. But the non-growing winter season is about 1/4 the lenght of Boston, so it's okay if things don't last as long.

Bruising/Harvesting
There is an art to harvesting the produce so as to minimize bruising, because bruised produce will go bad very quickly. We also have to learn how to quickly identify the produce that does get bruised and used up those ones for the harvest feast, and put them at the "front" of the root cellar so that they get used 1st before they go bad, and also release gasses and spores that will make the others go bad faster.

AirFlow
Avoid airtight plastic container for your produce, unless the goal is fermentation (control rot).