Growing Kale and Winter Salad Leaves Outdoors

Why the Cold Months Are Worth Gardening For

There is a particular pleasure in walking down the garden on a grey January morning and coming back with a colander of leaves. The plot may look sulky and half-dormant, but winter is not a closed season — it is simply a slower one. Kale and the hardiest salad leaves keep growing, if slowly, whenever the soil is above about 7°C. Growth does not stop, it dawdles, and a few sensible choices mean you can eat from the garden right through to spring.

The key is to accept a change of pace. Instead of expecting a flush of growth like you would in June, think of winter cropping as a slow withdrawal from a bank account you filled in late summer. Choose the right varieties, give them a little shelter from wind, and protect the ground from sitting wet and cold, and the rewards are generous.

Hardy Kale Varieties That Earn Their Space

Kale is the backbone of the winter plot. It shrugs off frost, and many varieties actually taste better after a cold snap, because the plants convert starch to sugar as a natural antifreeze. That is why December-picked kale is sweeter than the same leaf in September.

• Cavolo Nero (Nero di Toscana) — tall, dark, blistered leaves that stand through snow and crop for months if you keep picking.
• Red Russian — softer, more tender leaves with purple stems; superb young in salads, and reliably hardy.
• Winterbor — a curly, vigorous type bred for cold weather, with heavy yields from autumn onwards.
• Dwarf Green Curled and Pentland Brig — classic British sorts that crop steadily and cope with exposed sites.

Sow kale in modules from late May to mid-July, and plant out by early August so plants are well established before the cold arrives. Space them about 45cm apart; crowded plants sulk and rot. A later sowing in August will give you a smaller but welcome spring crop. Pigeons adore kale, so net it as soon as it goes in the ground.

Salad Leaves That Shrug Off Frost

Forget tender summer lettuce. Winter salads are their own genre: peppery, nutty, and often more interesting than anything you can buy. Sow from late August to mid-September, either in a sheltered bed or under cover, and pick a few leaves from each plant rather than cutting whole heads.

• Corn salad (lamb's lettuce) — the workhorse of winter, tough as old boots and mild and nutty in flavour.
• Land cress — a watercress substitute that grows happily in open ground all winter.
• Claytonia (winter purslane) — succulent, almost fleshy leaves that survive hard frost and self-seed helpfully.
• Mizuna, mustard 'Red Giant' and wild rocket — quick, punchy leaves for mixing into a bowl.
• Winter lettuces such as 'Winter Density', 'Arctic King' and 'Rouge d'Hiver' — hearting types that cope with cold and short days.

A row of these, sown thickly and cut regularly, will keep a household in salad with very little effort. Chervil and flat-leaved parsley also earn a place, giving you fresh green herbs when the rest of the herb bed has given up.

Cloches, Fleece and Windbreaks

Wind does more damage than cold. It strips moisture from leaves, batters tender growth and chills the soil. A simple windbreak — a length of netting or a woven hurdle — on the prevailing side of the bed will raise the temperature around your plants by a useful degree or two. A south-facing wall or fence is the best site of all, as it soaks up heat during the day and releases it slowly overnight.

Cloches then finish the job. Glass bell jars, plastic tunnel cloches and homemade hoops draped with polythene all work, and even a single layer of horticultural fleece can lift the temperature by two or three degrees — often the difference between surviving and thriving. Lift or vent cloches on mild, sunny days to let air move through, otherwise damp sits on the leaves and rot sets in.

Looking After the Soil Through Winter

Cold, waterlogged soil is the real enemy. If your plot is heavy clay, grow your winter crops in raised beds or add grit and plenty of well-rotted compost to improve drainage before planting. Never feed with a nitrogen-rich fertiliser at this time of year: it pushes soft, sappy growth that shatters at the first frost.

Keep the bed tidy instead. Remove yellowing or fallen leaves promptly so slugs and mould have nowhere to hide, and mulch lightly with compost to insulate the soil surface. Water sparingly, if at all — rain usually does the job — but do check plants under cover, where the rain cannot reach. Slugs and pigeons remain the main troublemakers, so keep netting and evening patrols going.

Harvesting and Making the Most of It

Pick kale by taking the outer leaves and leaving the tight growing crown in the middle to keep producing. Strip a plant bare and it stops. Salad leaves are best cropped little and often, snipping a handful from each plant so the row stays productive for weeks.

For a really hard spell, lift whole salad plants with a good rootball and heel them into a bucket of moist compost in a cool shed or greenhouse, where they will hold for weeks. In the kitchen, a frost-kissed kale leaf deserves more than a side dish: shred it into soups and stews, wilt it with garlic and chilli, or fold it through mashed potato with plenty of butter. Winter greens are not a compromise — cooked well, they are the best thing on the plate.