Winter lettuce: sowing, transplanting and protection
In the UK, sow a winter lettuce variety in September or October under cover, or in a mild garden under a cloche or cold frame. Thin and protect plants according to their type and site.
By Marmanda3 min read
To grow winter lettuce in the UK, choose a variety suited to cold-season growing and a sheltered route for a spring crop. The RHS recommends sowing under glass or, in a mild area, under a cloche or cold frame. The variety and amount of shelter decide whether plants establish well enough to carry through winter.
Pick a winter variety, not just a winter date
Read the packet for winter hardiness and the expected type of lettuce. Cos, crisphead and loose-leaf varieties do not need the same final spacing. A winter variety such as ‘Winter Density’ is one example in the RHS guide; use the packet to choose a cultivar sold for this purpose. Lettuce is different from lamb's lettuce, which is a separate crop with a separate growing schedule.
Choose a bright, sheltered position where soil drains and retains enough moisture for steady growth. The RHS favours a sunny site and warns that summer heat can trigger flowering, but for an autumn and winter crop the practical question is whether the plants get light without sitting in cold, saturated ground. A cover reduces exposure; it does not substitute for a suitable bed.
Sow in September or October under cover
For spring harvest, sow a winter lettuce in September or October in a greenhouse border or container. In a mild UK garden, a cloche or cold frame can provide shelter. If sowing outdoors in rows under protection, the RHS method gives a depth of 1 cm and 30 cm between rows. Sow thinly so seedlings have room to develop and the row is easy to thin.
Keep the seedbed evenly moist. If you prefer to raise seedlings in trays, sow into moist seed compost and keep them bright; prick them into individual modules once they have a few leaves and are sturdy enough to handle. Tray-grown seedlings can be hardened off and planted outside when spring conditions allow. This step applies to the tray route, not to plants growing in a greenhouse border.
The French SNHF lettuce page also gives a September–October nursery window for winter lettuce. Its nursery method is a brief French comparison; the RHS dates and shelter choices above are the UK approach. Use the seed packet and local exposure to decide whether a cloche, frame or greenhouse is the practical option.
Thin or transplant to match the lettuce type
For an outdoor row, thin seedlings gradually to 15–30 cm apart, as the RHS advises, and check the packet for the variety's exact spacing. Smaller loose-leaf types need less room; hearting lettuces need space to form a head. The RHS suggests about 30 cm for larger hearting plants and about 15 cm for loose-leaf varieties.
If you raised plants indoors, harden them off before moving them outside. Set the root ball at its previous depth, firm gently and water in. In colder regions or during spring establishment, a cloche or fleece can help plants settle. Remove or open cover during mild spells so air circulates and the crop does not remain enclosed in damp conditions.
Keep the bed fresh and harvest as plants mature
Check soil moisture under cover, as rain may not reach the bed. Water when the surface dries, then let excess drain; lettuce needs moisture but not standing water. Remove weeds while they are small. If seedlings disappear or leaves are damaged, inspect the bed and use targeted hand checks and physical protection.
Write down the variety, sowing date, cover and final spacing. That record helps distinguish a timing issue from a variety or site issue next season. The vegetable sowing and planting calendar gives a broad seasonal view; the guide to growing lamb's lettuce covers a different crop. For bed planning, see the beginner's vegetable garden plan.
References: RHS, Lettuces; SNHF, Laitues (in French).