The Basement Root Cellar – Yes! You can have one!

Due to Covid-19, there seems to be a renewed interest for many people to become more self-sustaining. Chickens are flying (pun intended) out of stores faster than ever to those who desire their own backyard flocks. Many others are worried about food production and distribution and have taken to gardening in an effort to grow their own food. Perhaps it is a part of the “Back to the Basics” trend or a revival of Victory Gardens which were common during the 2nd World War. In any case, whether you are raising your own meat, fruits, or vegetables, a storage plan for your products is crucial. We use a multitude of storage options on our hobby farm including freezing, canning, and storage in our basement root cellar. While many know how to can and freeze product, the root cellar seems to be an idea of yesteryear. With its’ functionality, energy conservation, and effective storage options, root cellars can be a successful part of food storage. With its’ relevancy to today’s world, the root cellar will be the focus of this article. About 20 years ago, we caught the gardening bug. My father, Gerald, started with Perennials like rhubarb and asparagus. He also grew giant pumpkins. The grandkids loved the pumpkins and he grew one pumpkin over 700# which took 3 rd place in the Minnesota State Fair. As we all took more interest in gardening, or mostly eating, we decided we can’t eat giant pumpkins unless we wanted to bake 500 pies. So, Grandpa Jerry focused his efforts on edible produce. In our experience, produce tastes better when grown fresh in the garden. My father loved acorn squash and planted a plot the next year. We had enough squash to last for 2/3 of the winter, but soon discovered that 100 squash didn’t fit in the refrigerator. At this point, he got the idea for a Root Cellar. A century ago, most people had a root cellar for long term storage of home grown produce and it got him thinking, why can’t we? In short, we can!! And I do!! This is how: Root Cellar Basics Historically, root cellars were dug out leaving a large underground room in the back of their yard, under the house, or into the side of a hill. These root cellars typically had a dirt floor, dirt or wood walls and ceilings. Root cellars made sense because the underground temperature, below the frost line, is usually in the 50’s with high humidity. This was good for long term storage. The ideal temperature for long term storage is in the range of 40 to 50 degrees. Building an underground root cellar seemed like a lot of work, so Grandpa Jerry decided we could build one in the basement instead. With our root cellar, we can now store many root crops, and canning supplies, in an optimum environment. This year, we had squash until April! Picking the basement location and size for the Root Cellar Picking the ideal basement location is the first factor to consider. Pick a corner which is below ground. We chose the South East corner of our basement which had concrete block up the entire wall on both sides. This is important because the dirt on the outside of the wall is cool and will assist in keeping a lower root cellar temperature. The size of the root cellar is another important factor. Our root cellar is approximately 6’2”wide x 7’7”deep x 8’ tall. The entrance door is in the middle of the short side. When picking the size of the cellar, you must make allowances for shelving units and ventilation ductwork. Every design will be different based on the available space in your basement. We built shelves on all three sides of the root cellar. Thus, upon entrance, you have shelving on your left, right, and in front of you with an area to stand in the middle of it all. It is important to plan for the exact inside dimensions of the root cellar. Basic Construction Considerations By picking a corner location in the basement, you have already secured two walls. Thus, you only need to build two additional walls on the interior of the basement. Most basement walls are insulated. Thus, take off the sheetrock, plastic vapor barrier and insulation to expose the concrete block. This will make the cellar cooler long term. Save those materials as you can use them on the two interior walls. The two interior walls should be insulated to prevent the cool air from escaping. Build a new side wall and front wall with framing for a 32-inch insulated pre-hung service door. It is important the service door be insulated to keep cool air inside the cellar. Once the interior wall frames are built and the door is hung, we wired an outlet inside the cellar to run a fan, and wired a switch to the front of the cellar for a light that we hung inside the cellar. It is important to put the light switch outside the cellar as you will not be able to see in the cellar once complete. This allows you know if the light is on or off. We recommend using LED bulbs which use 90% less energy and are much cooler. You want to avoid adding unnecessary heat to the cellar. Sheetrock can then be hung on the outside of the interior walls, along with the insulation and vapor barrier, previously removed from the concrete block exterior walls, on the inside. Ventilation If you do not add ventilation, the temperature in the root cellar would probably be about 60 degrees. This is not cold enough for ideal long-term storage of produce and items will spoil sooner. Thus, we must create an intake that will bring colder air in from the concrete, exterior wall, when fall arrives. To do so, we drilled a hole to the outside, through the concrete block, and between the floor joists. We used 4-inch diameter ductwork to push through to the outside with an open intake cover. We capped the intake with a wire screen to keep out mice. We then covered the back side of the intake duct face with silicone caulk to fill in any small space between the duct and the wall. We used a 90-degree elbow and pieces of duct to run the duct down close to the floor where the cool air will enter the cellar. Half of our ventilation system is complete. Cold air now has a way in to the root cellar. Now that cold air is coming in, we need a way to let warmer air out. To do so, we made another hole near the top of the root cellar ceiling to evacuate warm air from the cellar. This hole is on an interior wall and covered with a vent. Cold air is heavier than warmer air, so cooler air will flow inward and downward from the outside and force warmer air out the top vent. This works by simple convection. Have a cap available to close off the intake duct when you want to stop the colder air flow. While the convection method works well, it isn’t perfect. We added a fan to evacuate the upper warm air from the root cellar more efficiently. This created a negative pressure in the air-tight root cellar and caused outside air to be drawn in through the intake vent. Do not turn on the fan unless it is colder outside than it is inside, or you will bring in warmer air. We also keep a thermometer inside the root cellar to check temperature. Ideally, we try and keep cellar temperature between 40 and 50 degrees, for longer term storage. Do not let temperature get below 32 degrees or spoilage will occur. What can be stored in the Root Cellar? Some garden produce items are best stored in the root cellar, and others are best when canned or frozen. Items which store best in the root cellar include squash, potatoes, onions, garlic, carrots, broccoli, turnips, and rutabagas. Items which are stored best by canning or in a freezer include apples,tomatoes, raspberries, rhubarb, and other fruits. When apples and other fruits (which are acetic in nature) age, they give off ethylene gas which shortens the storage life of the more stable items of produce in the cellar. Thus, we Can apple sauce, tomato puree for stew bases, soups, and chili, pizza and spaghetti sauce, salsa, etc… We also freeze many items including raspberries, rhubarb, apple pie mix, etc… By storing the correct items in this manner, we extend the storage life of our root cellar vegetables. In summary, a root cellar can be a very affordable, energy efficient, way to store crops longer. By using two existing walls, you only have to build two more and install an insulated door to be on your way.Some affordable supplies to create the flow of convection and you are there. We also store our canned goods in the root cellar as we believe our canned produce will also last longer being stored at those temperatures. We are very pleased with our modern “indoor” root cellar. It has created a dedicated, energy efficient area for us to better conserve our crops. It saves us money and extends food shelf life. It is our belief that you, too, can build and benefit from, a basement root cellar.