The UK season for wholehead lettuce begins around the middle of May and finishes at the end of October. For salads in general, if the spring has been warm, the first seedlings will be planted around mid March and the first harvest will take place around April. The new season’s leaves are packed and ready on supermarket shelves within as little as 24 hours. Outside of the season our members produce crops on their own farms in Europe.
Most of the lettuce grown in the UK is grown outdoors, however, about 20% is grown in glasshouses. It is usually butterhead lettuce and some speciality leaves which are grown in this way, however, Iceberg is never grown under glass and it is unusual for Cos/Romaine to be grown in this way.
Some varieties are more suited to indoor growing i.e. round lettuce, which may damage outdoors. Generally, indoor crops will be crops which require temperature control such as tomatoes or peppers. The majority of lettuce is grown outdoors, due to the vast areas required for production and the extra costs involved in glasshouse production.
It depends on the season, as the warmer it is the faster the plants grow. In the early and late part of the season leaves take on average 2½ months to grow while in mid-summer, at the height of the season, the growing time is between 6 and 8 weeks.
For loose leaf varieties, the growing time can then be anything from 28 to 70 days, depending on the weather. The warmer it is the faster the plants grow.
BLSA members are made up of salad growers around the UK. The Association ensures that members are kept informed of market and technical developments able to advise members on a number of issues from legal and technical through to current industry advances and best practice. Click here to register your details to find out more information about becoming a member.
Pesticide use has been substantially reduced on salad farms over the years and we are now using much more environmentally friendly products. The salad industry’s own controls are far more stringent than those laid down by legislation.
Today many pesticides are target-specific (designed to tackle a specific problem or insect) with little or no environmental impact. Salad growers operate ‘Integrated Crop Management’ techniques in which a variety of control measures are used and sprays only applied where necessary in response to an identified problem.
Crops are intensively monitored for signs of pests and disease before any decision is taken to spray. Crop traps (much like fly traps) are used to see how many pests are actually around. Many farms also use sophisticated weather stations to monitor conditions likely to produce high levels of disease. With this early warning system, appropriate action can be taken to avoid loss or damage to the crop, such as the protection of the salads with vast carpets of mesh anti thrip nets laid on to wire hoops across the field (a thrip is one of the tiniest known pests).
Other methods used include the planting of specific crops to attract predators which will eat the pests, the use of natural products to repel insects and the use of vacuum units to remove insects ahead of harvest.
With baby salad leaves, the growing cycle is so short, sometimes just 24 days, that many crops are never sprayed at all.
Farmers exercise strict crop rotations and are also continually testing different varieties of salad leaves for their disease resistance in order to minimise the use of pesticides.