This may just be the keystone to the home-grown food arch I'm living right now. I've grown a lot of produce in other years, but storage has always been less than optimal. Keeping crate upon crate of roots in the basement of the old farmhouse worked for a few months, but the conditions were not great. The ideal root cellar holds just above freezing at high (90+%) humidity. In the old dirt-floored house basement where we used to put up the year's bounty the temperature swings were too great - too warm initially and then some years too cold (below freezing). And the humidity was never high enough. I could partially overcome the "low" humidity by packing the crops in damp sawdust, but it still dried out over time and remembering to dampen it did not always happen.I knew a good root storage set-up was necessary to pull off a whole year of ultra local eating, and last summer I pulled the trigger on a good cellar. The basic idea for the cellar came from Mother Earth News. I adapted it to my particular situation with a tweak here and a tweak there, but the design is a big septic tank (new, not used!) with a hole cut through a wall. In the photo above you can see the vent pipes so the roots can get fresh air. There is a second pipe deeper in as two vents are vastly better than one. So far I'm pleased with the cellar's performance.
I used a large tank - so big it came in two pieces. I think the external dimensions were 8 x 8 x 12 feet. On the opening image of the post the seam between the halves is visible at roughly belly button height.
To keep the dirt from caving in on the door I built cinderblock retaining walls. Perhaps it's not the most beautiful structure known to man, but it's functional.
The weather this fall was warmer than average so it took longer than expected to get the interior cooled to good storing temperatures. Also the humidity was kind of low initially - perhaps from the concrete continuing to cure? Once the shelves filled out with live roots though, the humidity went up to 90+% and has stayed there ever since. Now that we're well into January there is a minor issue with the door. The humidity on the inside condenses on the door, drips down and freezes at the threshold, making it quite difficult to open the door sometimes. I need to fabricate a little skirt for inside the base of the door to force the drips an inch deeper into the cellar where they won't seal the door as they drop.
There are other less expensive ways to store a lot of roots. One traditional method is called a clamp, which is basically a hole in the ground lined with straw, sawdust, or stemmy hay. Some do without the liner at all. The roots pile into the hole and then get covered back over with straw and dirt. This is an inexpensive method, but it has drawbacks. Rodents can find the cache and cash-in. Digging through two feet of snow and/or mud every week or so throughout the winter would get old. In the spring when the thaw hits a hole that doesn't have good drainage it is prone to pooling. And in later spring as the temperature rises those roots might try to grow. Growing is a sure way for the roots to use their saved calories on themselves, instead of being available for my belly.
People also make clamps out of old refrigerators and other like appliances. Almost any box with a door could potentially work. In order to have enough storage capacity though I would have needed to bury a bunch of units - and at that point the labor is just as great or greater than building a proper cellar.
If you like the idea of storing a bunch of roots and want to know more, I learned a lot from, Root Cellaring, by Mike and Nancy Bubel.