Lettuce (Lactuca sativa) is a temperate annual or biennial plant of the daisy family Asteraceae. It is most often grown as a leaf vegetable. It is eaten either raw, notably in salads, sandwiches, hamburgers, tacos, and many other dishes, or cooked, as in Chinese cuisine in which the stem becomes just as important as the leaf. Both the English name and the Latin name of the genus are ultimately derived from lac, the Latin word for “milk”, referring to the plant’s milky juice. Mild in flavour, it has been described over the centuries as a cooling counterbalance to other ingredients in a salad.
The lettuce plant has a short stem initially (a rosette growth habit), but when it gradually blooms, the stem and branches lengthen and produce many flower heads that look like those of dandelions, but smaller. This is referred to as bolting. When grown to eat, lettuce is harvested before it bolts. Lettuce is used as a food plant by the larvae of some Lepidoptera.
Lettuce is grown commercially worldwide, hardy to Zone 6, requiring light, sandy, humus-rich, moist soil. Dry conditions can cause the plants to go to seed (known as bolting). It is normally grown by early and late sowing in sunny positions, or summer crops in shade.Ideally, lettuce plants require a rich, humous-laden soil that will hold moisture in the summer. They may require the soil to have lime added as a soil pH of 6.5 is just right. Quite often though, lettuce is grown between rows of slower growing plants like brussel sprouts or broccoli etc. This is called a catch crop. Water is a vital ingredient and lettuce prefers the soil to be moist at all times. Lettuce plants do not like hot sunny conditions, preferring a lightly shaded site for summer varieties.
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