Lettuces fall into three groups — bread , cos , and loose - leafage . The cabbage kinds are subdivide into crispheads and butterheads . Those sold by the grocery stores are almost always butterheads because crispheads do not travel well and wilt rather quickly after harvesting . The cos varieties have recollective , boat - shaped , very crisp leaves and are prefer by many for their delicate flavor . Loose - leaf simoleons are more prevalent in the United States than here , although one American motley , ‘ Salad Bowl ’ , is liked by many gardeners .
Any check to unfluctuating ontogenesis is nonimmune to result in rather inadequate lettuces . Water is crucial , but the dirt must be sufficiently poriferous for good drainage . Although late summer lettuces will tolerate the spook cast by rows of taller vegetable , earlier sowings demand an open , unshaded site . The soil should have been dug well during the winter excavation program , and organic manures in the variety of farmyard manure , garden compost , or spent hop should be applied generously .
These manures are invaluable in aid to retain ground wet . If he is able-bodied to use nursery cold frame of reference and cloches , the good gardener is able to raise lettuces for at least six month of the year . The yield of winter and other spring lettuces is not easy and these crops are a challenge to the gardener . sure stalwart varieties for April cutting may be over - wintered in the out-of-doors in favorable areas , but much depends on the winter weather observe the autumn sowing .
Outdoor sowings may be made in March in the S - west and during the first two weeks of April in other areas . Here again , cloche are utile . Sow as thinly as potential in 2.5 atomic number 96 ( 1 in ) deep drills spaced 40 cm ( 15 in ) apart . Keep down weeds by hoeing and lose weight the seedlings to 30 centimetre ( 1 ft ) apart when three or four leaves have formed . The thinnings from March , April and May sowings may be used to make furtherrows .
A sowing made in late July render lettuces in November and December , but the weather plays an important part here . The rows involve cloche protection from October onwards . For early spring supplies , seed in the cold frame in September and replant the seedling in the greenhouse or in frames . Alternatively , inseminate in the glasshouse in other October and transplant when the plants have four leaves . recondite planting at any time is inexpedient . It is in particular dangerous where lettuces are to be over - wintered . Over - crowd must also be avoided , and right ventilation system is very important .
Birds often peck at loot seedlings and plants . A few strand of black cotton fixed above the quarrel prevent this problem . Although present - day cos varieties are look upon to be ego - folding , better nub form if the plants are tied rather loosely with raphia or gentle string . at large - leaf varieties are less prone to bolt than cabbage and cos works . Instead of slue the whole plant , leaves are picked as and when required from sluttish - folio variety .
Among the many varieties on offer , the followers may be relied upon for worthwhile crop .
For outside sowings from March until July ‘ Sutton’sImproved ’ , ‘ Unrivalled ’ , Trocadero ’ , ‘ Webb ’s Wonderful ’ , ‘ Giant White Cos ’ , ‘ Salad Bowl’ . To stand the winter out of doors‘Stan - stead Park ’ , ‘ Arctic King ’ , ‘ Brown Cos ’
