Sow a short row every fortnight to ensure continuity of cropping.
Sow seed thinly 13mm (0.5in) deep in rows 30cm (12in) apart.
Time of sowing depends on when the crop is wanted:
For a summer/autumn crop: sow outdoors from late March to late July. For an even earlier crop, sow with heat in early February and plant out in early March under cloches or plastic; pre-warm the soil for two weeks first.
For an early winter crop: sow outdoors in early August and cover the plants with closed cloches in late September.
For a mid-winter crop: sow in a heated greenhouse in September and October and grow on in the greenhouse.
For a spring crop: sow a cultivar such as 'Winter Density' in September/October either in a cold greenhouse or outside under cloches in mild areas.
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.
Start thinning as soon as the first true leaves appear and continue until the plants are 30cm (12in) apart, 23cm (9in) for dwarf, compact cultivars and 15cm (6in) for loose-leaf types. If you water the soil the day before thinning and do it carefully, the thinnings can be planted out to give a slightly later crop. Thinnings can also be picked and eaten.
Water when the soil is dry; the best time to water is in the early morning.
Early in the year sparrows can be a problem as they find young lettuce plants irresistible. Protect with fleece, chicken wire or similar.
Lettuce is ready to cut when a firm heart has formed; the exception to this is the loose-leaf types where leaves are harvested as and when needed. It is best to cut in the morning when the plants will be the freshest.
