Lars Lund

08 Sep 2020 14:34

Winter storage of vegetables

Winter is coming, and the first night-frost is here. The problem is then where the healthy and vitamin-rich tubers should be stored, so they can survive the winter.

In houses with basements, it is rarely a problem. You can always find a cold dark corner in a basement for the potatoes, carrots and other root vegetables that do not tolerate frost. Modern houses rarely have a basement and even if you purchase an extra fridge for the crops, it is a costly matter.

In the good old days, they made clamps. You can still find them, but they are mostly used for turnips. It is a quite difficult method. First, you dig 8 inches into the ground with a breadth of 40 inches. The potatoes and other vegetables are then piled up in a triangle. You should then scatter sand in between the vegetables, so they last longer. All of it should be covered with 4 inches of straw, and the straw is then covered with soil. The soil can be from a trench and should be at least be 15 inches thick, so it can drain off any water. Instead of soil and straw, you can also use winter mats. They should be at least 7.8 inches thick.

A substitute to the clamp is a root cellar which is much easier to handle. Root cellars are very popular in both Sweden and Norway. It takes a lot of digging to make a root cellar, but with nice timber, you can make your own. You can also buy complete root cellars made from glass fibre. A complete root cellar is approximately 4,800 pounds.

Simple clamp

In small gardens, there are some easier solutions. One of the readers told me about this simple method for root crops and potatoes. You dig a fitting hole for a portion of potatoes. The hole should be lined with straw and the potatoes are put in. Instead of keeping it dry, it should be kept wet. You can use the hose for that. Then cover the hole with straw. The humidity will create a nice environment for the potatoes, so they will taste like they are new. Make sure the potatoes are not damaged, otherwise they will rot.

The footing method

A more long-term solution, which also suits fruit, is to make use of the footing of the house. Under the house roof and close to the footing it is usually dry. As almost nothing can grow by the footing, many have covered the area with tiles or stones.

You can dig a square hole by the footing. Put up three walls of LECA blocks, the fourth side being the footing. Then you have a small homemade cellar. The deeper you dig the hole, the more LECA blocks you need, and the more you can fit in the hole.


Put a layer of 4 inches of pebbles in the bottom and cover with a wire netting or a board with holes, to elevate the vegetables from the pebbles. You can pile up the vegetables in boxes, so they are easier to reach when you need them.

Ideally, the cellar should get air, so waste heat and humidity can get out. That can be done by drilling some holes in the LECA blocks and put in a hose or pipe, which reaches the surface and bends so no water will enter. If that is too difficult then open the lid whenever there is no frost. The lid is supposed to hinder mice from eating the vegetables. You can make a lid from a waterproof slab with polystyrene at the bottom.

You can build a cellar like this in both the greenhouse and carport, but it is more practical if the cellar is not placed far away from the house.

Shaft ring

An outdoor cellar can also be made from a barrel or a large shaft ring buried in the ground. Put a 4-inch layer of pebbles in the bottom. Place the vegetable boxes in there and make sure there is an air drain which goes through the lid.


The polystyrene solution

You can buy a polystyrene barrel or box made for this purpose. They are suitable for all kinds of vegetables, but not for fruit. If there is a heavy frost, the polystyrene might be too thin. Then it is necessary with more coverage.

Om Lars Lund

Lars Lund
Danish horticulturist and journalist
Lars Lund has for many years engaged in the garden and greenhouse. Lars has published many books about greenhouses, and he has participated in many Danish horticultural TV shows. He is a walking garden encyclopaedia, and he has answers for most basic cultivation questions – also the more ambitious ones.  

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