Tip of the month: September

How to store vegetables for winter

Even the most experienced veg growers can end the season with an excess of one or more types of vegetable. In fact, I think it’s a sure sign of a successful year. Furthermore, having an end-of-season glut means you can squirrel them away to enjoy throughout the winter. There are several ways you can keep them in tip-top condition, depending on what left-over crops you have to store.

Tools for the job

Where to store vegetables?

• In the ground
• In a traditional clamp
• Boxes of sand
• Paper sacks
• Nets and stockings
• Dried in jars
• In the freezer

Leave in the ground Really hardy crops, like Brussels sprouts, winter cabbages and leeks can be left in the garden until needed. But if you have a well-drained soil, many root crops, including carrots, swedes, turnips can also be left where they were growing. Make sure you mark where each row of root vegetables is, so that you can find them once the tops die down. To keep them safe, you will need to insulate the root crops with a duvet of straw, held in place with polythene, so that they can be lifted during frosty conditions. The exception to this rule is parsnips, which actually improve in flavour after being exposed to frost. Bear in mind you will lose some to slugs and snails – but damage is usually limited to the top of the root that you would cut off in any case.

Traditional clamp Before the days of fridges and freezers, root crops were stored outside in piles of sharp sand, known as ‘clamps’. Each clamp was constructed from alternate layers of sand and harvested roots, arranged around a central ‘flue’ of straw that aided ventilation. The stack and flue may be was built up, layer by layer, until the clamp was complete. The roots could then be removed as required. It maybe an old technique, but it works and is worth a try if you have a lot of root crops to store.

Lift and box-up On heavy soil, root crops such as carrots, parsnips, swedes and turnips will succumb to pests and diseases if left in situ, so they need to be lifted and stored in boxes of damp sand. The damp sand will prevent the roots from shriveling. Store only perfect roots in layers of sand until the tray or box is filled. Then the boxes need to be placed in an airy, cool, but frost-free, dark place, such as a garden shed, cellar or garage. This is also a good way to store beetroot, which would be harmed by sub-zero temperatures if left outside in the garden during the winter months. Lift the roots carefully so that you don’t damage them and clear them of soil making sure you handle them gently. Twist off the foliage from beetroot to prevent them bleeding, but all other crops can simply be trimmed with a knife or secateurs.

Paper sacks and nets A few vegetables need to be stored dry. Potatoes, for example, are best placed in special double-thickness paper potato sacks punctured with ventilation holes. Once filled, these need to be stored in an airy, cool, frost-free place that’s kept dark. This is essential to prevent them sprouting. Winter cabbages, onions, marrows and pumpkins also should be kept dry, but this time placed in the light in trays, nets or in the case of onions – plaited into strings. Onions in particular, must be ripened off thoroughly before storage. If plaiting is too fiddly for you, use old tights to hang fully-ripened onions with a knot between each bulb, so the bottom onion can be snipped off the string without disturbing the other bulbs.

Storing dry in jars Seed crops, such as peas and beans, can be stored dry in sealed jars or boxes. Leave the pods to mature on the plant and then pick and dry the swollen pods on racks or trays in an airy room or greenhouse. Once crispy, the pods can be opened and the seeds removed then placed in a clean and air-tight jar or box.

In the freezer The freezer should be treated as a last resort for vegetables that won’t store successfully in any other way – otherwise your freezer will be full before you know it. Most vegetables can be frozen for up to year. The freezer is a good choice for aubergines, asparagus, peas and beans, courgettes, sweetcorn, tomatoes, sprouting broccoli and Brussels sprouts. Pick the vegetables in their prime, most will need blanching for long-term storage, but can, if you prefer, be frozen for a few weeks without blanching.

Happy gardening!