There is a particular pleasure in lifting the lid of a cold frame in January and finding a tangle of bright green leaves waiting underneath. While the vegetable beds are doing their annual impression of a muddy field, containers and frames quietly carry on producing something fresh, peppery and worth dressing with a little olive oil. Winter salads are not difficult, but they do ask for a different approach to sowing, watering and shelter. Get those three things right and you can be cutting your own leaves from October right through to April.

Why grow salad in the cold months?

Shop-bought winter salad is expensive, and the bags of mixed leaves on offer have usually travelled a long way to reach a supermarket shelf. Home-grown leaves, cut minutes before they hit the plate, taste markedly better. More importantly, many of the classic winter salad plants are genuinely hardy. They do not merely survive the cold, they prefer it. Sow them in late summer and they will tick along slowly through the darkest weeks, putting on enough growth for a regular picking whenever the weather allows you outdoors.

There is also a practical argument. Containers and cold frames give you control. You can raise pots onto feet or bricks to keep them out of standing water, move them against a south-facing wall when a cold snap is forecast, and cover them with fleece in seconds. That level of protection is far harder to arrange across an open plot.

Varieties that earn their place

Forget the tender summer lettuces for now. The winter stalwarts are the ones to build your sowing plan around:

• Lamb's lettuce (corn salad) — the backbone of any winter crop. Sow 'Verte de Cambrai' in September and it will stand through hard frost, forming neat rosettes of mild, nutty leaves.
• Winter purslane (claytonia) — succulent, spoon-shaped leaves with a fresh, almost spinach-like flavour. It self-seeds obligingly once established, so a single sowing can keep going for years.
• Land cress — a reliable substitute for watercress, with a proper peppery kick. Happiest in a cool, shaded frame.
• Wild rocket — far hardier than the annual sort, with finely cut leaves and a long, slow burn of heat.
• Mizuna and mustard greens — quick, cheerful and decorative, though they will need the protection of a frame in a severe winter.
• Winter lettuces — 'Winter Density', 'Arctic King' and 'Valdor' will hold in a cold frame where they would sulk outdoors.

A packet of each, sown in succession, gives you variety without a great deal of expense.

Choosing containers, compost and a frame

Depth matters more than width. Aim for at least 20cm of compost, ideally 25cm, so roots have room to forage and the pot does not dry out or freeze solid in a hurry. Terracotta looks lovely but cracks in a hard frost, so glazed ceramic, plastic or wooden troughs are the safer bet. Whatever you choose, check the drainage holes are clear and stand the pot on feet, bricks or a couple of battens so water can escape freely.

Use a soil-based potting compost rather than a light multipurpose mix, and fork through a handful of horticultural grit per pot to keep it open. Soil-based compost holds its structure through months of wet weather and buffers the roots against fluctuating temperatures. Do not be tempted to reuse compost from last year's tomato pots: it will be exhausted and may harbour vine weevil grubs.

If you have a cold frame, so much the better. A simple wooden or aluminium frame against a south-facing wall is the single most useful piece of winter kit a kitchen gardener can own. No frame? A cloche, an old double-glazed window propped on bricks, or a layer of horticultural fleece draped over a hoop will all do a decent job.

Sowing for a steady supply

Timing is everything. Start sowing lamb's lettuce, land cress and winter purslane from late August to mid-September. These early sowings put on good leafy growth before light levels drop. Follow with another sowing in early October for a late-winter crop, and a final one under cover in a frame in November if you have the space.

Sow thinly, barely covering the seed, and water gently with a fine rose. Germination is quick while the soil is still warm. Thin the seedlings to roughly 10cm apart once they are large enough to handle, and use the thinnings in a sandwich. Crowded seedlings are the main cause of weak, mildewed winter crops.

Protecting pots from hard frost

Frost is rarely the killer that wet is. Waterlogged compost, freezing solid around roots, does far more damage than cold air alone. So keep pots off the ground, water sparingly and only in the morning, and never let them sit in a saucer of standing water through the winter.

When a sharp frost is forecast, drape fleece over the pot or close the frame lid. On milder days, open the frame to let air circulate, otherwise damp, still air encourages botrytis and mildew. A little ventilation on a bright January afternoon makes a surprising difference. Slugs and pigeons remain active in all but the hardest weather, so check under pots and net anything vulnerable.

Harvesting and keeping the crop coming

Pick individual outer leaves rather than cutting the whole plant, and most of these crops will regrow. Lamb's lettuce and purslane respond particularly well to this treatment, giving you repeated cuts from the same rosette. Take only what you need for a meal, and leave the rest to grow on.

Growth will be slow, so be patient and resist over-picking in December. A weak liquid feed every few weeks in late winter, once daylight lengthens, will push plants on for a spring flush. By March the frame is usually full of fresh growth again, and you can begin sowing the next generation. Winter gardening rewards a bit of forward planning, but the reward — a bowl of clean, peppery leaves on a cold day — is well worth the trouble.