What Root Vegetables Really Want

Carrots, beetroot, parsnips, swedes and potatoes come out of the ground wanting roughly the same thing: a cool, dark, slightly humid place with a little moving air. Get those conditions close to right and most roots will sit happily for three to six months. Get them wrong and you will be composting a summer's work by Christmas.

The difficulty is that few British homes have a cellar. What they do have, if you look properly, is an under-stairs cupboard, a garage corner, an unheated spare room or a shed shelf. Any of these can be pressed into service with a bit of preparation.

Aim for 0°C to 5°C for carrots, beetroot and parsnips, and slightly warmer — 4°C to 8°C — for potatoes. Darkness matters more than most people realise: light turns potatoes green and bitter, and encourages everything else to sprout. Humidity around 90 per cent stops roots shrivelling, but you still need ventilation, because stagnant damp air is what brings on mould.

Only Store the Best of the Crop

The single most useful rule is to store only perfect specimens. One rotting carrot in a crate of sand will spread spoilage to its neighbours within weeks, and by the time you notice the smell it is usually too late for the rest.

• Do not wash anything. Washing introduces moisture into every scratch. Brush off dry soil with your hands or a soft cloth instead.
• Reject the damaged. Fork punctures, splits, slug holes and soft patches all mean a root destined for the pan this week, not the crate.
• Cure for a few hours. Spread roots on newspaper in a dry, airy, frost-free spot for an afternoon so the skins firm up.
• Trim carefully. Twist or cut leaves back to about 2cm above the crown. Cutting flush makes beetroot bleed and carrots weep.
• Handle potatoes gently. Let them dry for a day, keep the skins intact, and never wash them before storage.

The Sand Crate Method

This is the traditional approach and it still works beautifully. You need a wooden or sturdy plastic crate, box or deep tray, and a supply of barely damp sand. Sharp sand or a mix of sand and spent potting compost both do the job. The sand should be damp enough to hold its shape when squeezed in your fist, but never wet enough to drip. If water runs out, leave it to dry for a day before using.

Spread a 3cm layer of sand across the bottom. Lay the roots on top so that none are touching, then cover them completely with more sand. Repeat in layers until the crate is full, finishing with a good 5cm of sand over the top layer. Carrots and parsnips can go in upright with their crowns up, which is how they grew, or laid flat — both work.

Label each crate with the variety and date, stack them no more than three high, and raise the bottom crate on timber battens so it is not sitting directly on a cold concrete floor. Kept cool and dark, carrots stored this way will still be crisp in March. Check the sand every few weeks and mist it lightly if it has dried out.

Potatoes, and the Paper Sack Approach

Potatoes do not need sand. They want darkness, moderate humidity and air. Perforated paper sacks, hessian bags and cardboard boxes lined with newspaper all work well. Fill them no more than two-thirds full, fold the tops over loosely, and keep them somewhere genuinely dark.

Two partnerships to avoid: keep potatoes away from onions and apples. Onions release moisture that encourages mould, while apples and other ripening fruit give off ethylene gas that pushes potatoes into premature sprouting. A separate cupboard or the far end of a shelf is enough separation.

Sort through the crop before storing and again after a fortnight. Any tuber with a soft, dark or weepy patch should come out immediately — blight and soft rot travel quickly through a sack.

Finding the Right Spot Indoors

Kitchens are the worst place in the house for storage: warm, humid and full of cooking smells. Boiler cupboards and conservatories are equally unsuitable, swinging between hot and freezing. The best spots are dull, steady and out of the way.

• Under-stairs cupboards, especially those on an outside wall.
• Unheated spare bedrooms, pantries and back porches.
• Garages and sheds, provided you insulate against frost.
• Cellar steps and old coal stores, if you are lucky enough to have one.

If your only option freezes in a hard winter, wrap crates in old blankets, bubble wrap or a bale of straw, and stand them on a wooden pallet rather than bare concrete. A cheap maximum-minimum thermometer left in the spot for a week will tell you more than guesswork ever will. To deter mice, raise crates off the floor and check for droppings whenever you inspect the crop.

Checking, Troubleshooting and Enjoying the Result

Plan to look through your stores every two to three weeks. Lift the top layer of sand, feel a few roots, and remove anything suspicious at once. A single soft beetroot can be isolated and used, while the rest of the crate carries on perfectly well.

If potatoes begin to sprout, rub the sprouts off and use those first — they are still perfectly good. Limp carrots are best turned into soup, roasted or grated rather than eaten raw. Should the sand grow a faint fuzz of mould on the surface, scrape that layer away and leave the crate uncovered for an hour to dry out.

There is a real pleasure in digging a crate of sand in February and pulling out carrots that snap like they were lifted yesterday. It costs you a few crates, a bag of sand and an hour of sorting in October, and it pays you back all winter.