How to Grow Lettuce
Good crisp, succulent lettuce that will stand well without running to seed must be watered regularly during dry periods. By careful planning and the use of cloches and cold frames, it is possible to have home-grown lettuce practically the whole year round. Busy gardeners, how-ever, will doubtless prefer to save labour by growing only two or three varieties that will provide them with fresh lettuce during summer and autumn. Among such varieties, ‘Tom Thumb’ and ‘Little Gem’, both old favourites, rank very highly. The former is a dwarf cabbage lettuce with a tight solid head. It matures exceptionally fast. Little Gem is also compact, and is intermediate between a cabbage and cos type.
Good varieties include: ‘Sigmadeep’, a dark green butterhead lettuce, of upright growth, with few outside leaves and a crisp tender heart. A bonus for those with small gardens is the fact that its narrow shape allows the plants to be spaced more closely than other kinds of butterhead lettuce.
The crisp-hearted kinds of lettuce which are particularly resistant to bolting (running to seed prematurely) are good for middle and late summer, particularly in dry conditions. ‘Windermere’ and ‘Webb’s Wonderful’ are both slow to run to seed, even in times of drought, provided they are kept watered. ‘Salad Bowl’, popular on the Continent, is a cut-and-come-again variety with little or no waste, and a boon to busy gardeners. It is a non-hearting variety that produces abundant supplies of curled leaves over a long period. Ideally these should be picked while still young and tender.
Lettuce seed should be sown thinly in drills 15mm (5/8 in) deep and 30 cm (1ft) apart. As soon as two true leaves appear, thin to a distance of 15-30 cm (6-12 in) apart, depending on the size of the variety.