Growing Winter Salads

Use an unheated greenhouse for hardy leaves, with realistic expectations about winter growth. The aim is a useful supply to pick, not a promise that every sowing will grow at summer speed.

By Simon Adams · Updated 25 October 2026

Choose leaves suited to the season

Try lamb’s lettuce, winter purslane (claytonia), land cress and winter lettuce varieties. Mizuna, mustards and other Asian greens add different flavours and textures. Choose a small selection your household will eat, and check the packet for the variety’s sowing window and hardiness.

Keep different crops labelled. If a mixed sowing disappoints, separate rows or modules make it easier to see which leaf struggled and which deserves more space next year.

Start before the darkest months

August and September are useful UK planning windows for many autumn and winter salads. Sow while there is time for plants to establish, rather than waiting until the summer crop has left you an empty greenhouse late in the year. Modules can help bridge that overlap.

Dates vary with crop, variety and location. Colder continental winters and a mild coastal UK garden need different plans. If you have missed the main window, check a suitable late sowing or buy healthy young plants, and expect later picking rather than forcing the original timetable.

Give plants light and growing room

Winter sunlight is weaker and days are shorter, so growth and replacement leaves can be slow. Keep glazing clean and avoid putting salad containers beneath dense staging or taller crops. Extra warmth alone does not replace adequate light.

Use a greenhouse bed or containers with drainage and peat-free compost. Sow thinly and thin or transplant at the spacing recommended for the crop. Baby-leaf production and a mature lettuce head need different amounts of room; decide what you intend to harvest.

Water carefully and keep air moving

Keep establishing seedlings moist, then check the root area before watering. In winter, avoid keeping soil or compost persistently wet. Water in the morning when needed and ventilate in suitable conditions, balancing airflow with protection from severe cold.

An unheated greenhouse can freeze. Check its overnight minimum, not only the outdoor forecast. Suitable fleece can add protection in a cold spell, but it does not guarantee survival or rapid growth. Keep covers manageable so you can inspect plants underneath.

Inspect and harvest little at a time

Look for slugs, snails, damaged leaves and rotting material during your regular checks. Remove affected debris and avoid letting plants become a dense, damp tangle.

For suitable cut-and-come-again crops, pick a few outer leaves while leaving the centre to grow. Take only what the plant can spare, especially when replacement growth slows. Harvest what you need and wash leaves before use.

Plan the next changeover

Record sowing dates, first pickings and any gaps in supply. Note when the area must be cleared for spring crops. A modest winter trial gives you a useful basis for next year’s choices without committing the whole greenhouse to unfamiliar leaves.