Grow lettuces in full sun on moisture-retentive soil.
Sow a short row every fortnight to ensure continuity of cropping. Sow seed thinly, 13mm deep in rows 30cm apart.
Time of sowing depends on when the crop is wanted, but for an early winter crop, sow outdoors in early August and cover the plants with closed cloches in late September.
High soil temperatures in summer can prevent some cultivars from germinating. Sow in the evening, water with cold water and provide some shade to keep temperatures down.
Thin seedlings as soon as the first true leaves appear and continue until the plants are 30cm apart. The seedlings you thin out can be washed and eaten too.
Water when the soil is dry, ideally in the early morning.
Lettuce is ready to cut when a firm heart has formed, or for the loose-leaf varieties when leaves are big enough to be worth eating. Harvest lettuces by cutting rather than pulling.
Adapted from Royal Horticultural Society advice, www.rhs.org.uk