Lettuce is an odd vegetable, which is as often used for decorative purposes as for taste and nutrition. Shop-bought lettuces have much to answer for in this respect, as are the oft-repeated scare stories about their being full of chemicals. Home-grown lettuces not only have flavor, but you also know what they have been fed on. Another advantage of growing your own lettuces is that you can grow several different types and colors so that you can make a really attractive salad – and, of course, they are fresh. You can pick just as many leaves as you want right at the last minute.
Lettuces have been popular for a long time and were even depicted in carvings and paintings in Ancient Egypt. They were popular among the Romans, who are reputed to have introduced them to Britain. The original lettuces were probably quite bitter and needed blanching to make them palatable, much like endives today.
Modern gardeners are fortunate in having so many different types as well as a wide range of varieties. The main type is the cabbage or headed lettuce. These are either loose balls of soft leaves – butter head lettuces – or those with much firmer, crinkly-edged leaves – crisp heads. Cos or romaine lettuces are more upright and have long, crisp leaves and a succulent heart. Then there are the loose-leaved or non-heading varieties, which do not produce a heart but just a mass of loose, individual leaves. These lettuces are very good when you want to be able to take leaves as and when you require them. There has recently been a great deal of interest in these cut-and-come-again lettuces, and many new varieties have appeared. Ibis method of growing lettuces is far from new, however.
The mainstay of salads, lettuce is usually eaten raw, although tin increasing number of recipes include cooked lettuce. Lettuce leaves are also widely used as a garnish, for which the coloured forms of the loose-leaved varieties are particularly useful. There is now quite a wide range of red- and bronze-leaved forms, as well as green forms with decorative leaves.
Lettuces are not difficult to grow and, in theory, can be harvested till year round, but some type of protection is required for winter varieties. They grow relatively quickly and will be ready from 5 to 12 weeks after sowing, depending on the variety. This means that they can be grown among slower growing crops or used to replace another crop that has already been harvested.
Cultivation
Lettuces need an open, sunny position, although light, partial shade during the heat of the day can be an advantage in hot areas or during hot summers. The soil needs to be fertile and, preferably, moisture retentive, and this is best achieved by incorporating plenty of manure during the autumn dig. Lettuces can be sown straight in the ground or grown in trays and transplanted. It is a good idea to sow a short row of lettuces and then, instead of throwing away the thinning, to transplant them to make up the rest of the row. The advantage of this is that the transÂplants will take a few days to settle down and will produce a slightly later crop than the sown plants. It the whole row is sown at once, the lettuces will mature at the same time, which will probably mean that many are wasted. Transplanting is difficult after midsummer, because lettuces often rapidly run to seed.
Start early sowing in trays or modules under glass in late winter or early spring. Plant these out under cloches or in cold frames to gel an early crop. Seed can be sown directly in the soil from early spring onwards. Sow in shallow drills 1 cm deep, each row about 30cm/l2in apart. Thin the lettuces to 15-30 cm apart, depending on the size of the variety. Transplanted lettuces should be planted at the same distances, keep the soil moist and do not allow the plants growth to be checked or they will rapidly run to seed. Sowing alter midsummer will provide lettuces for autumn and early winter, bill cover them with cloches when necessary from around mid-autumn. Special winter varieties can be overwintered under cloches or grown in greenhouses or in cold frames.
Harvesting
Lettuces can be harvested whole or leaves can be taken from the plants as required. The loose-leaved varieties are usually picked leaf by leaf, but cabbage-type varieties can be picked in the same way if you wish. Hearted varieties are usually ready for harvesting as soon as they feel plump and firm. Do not leave them too long in the ground after maturing or they may bolt, bull the w hole lettuce from the ground or cut below the bottom leases if you want the plant to resprout. Loose-leaved varieties mature earlier, and leaves can be picked as soon as they are large enough, which is usually from about seven weeks alter sowing.
Storage
Whole lettuces can be kept in a refrigerator for a short time, but they are best used straight from the garden.
Pests and diseases
Slugs and greenfly (aphids) are two of the worst problems and should be dealt with by your preferred methods. Other pests can include root aphids and cutworms.
The main disease is downy mildew, and lettuces also tend to suffer from a few other fungal diseases. These occur mainly in wet seasons and are best avoided by making sure that individual lettuces are not planted too close together. This will ensure that there is plenty of air movement around the plants. If pests or diseases do get out of control, do not spend a lot of time and money on chemical control. Simply get rid of the plants and start again.
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