Lettuce is an annual plant of the daisy family, Asteraceae. It is most often grown as a leaf vegetable, but sometimes for its stem and seeds. Lettuce is most often used for salads, although it is also seen in other kinds of food, such as soups, sandwiches and wraps; it can also be grilled.
There are hundreds of varieties of lettuce you can grow, from soft and delicate bibb lettuce to crisp and colorful rouge d'hiver. This easy-to-grow annual is a classic for beginner and expert gardeners alike. Most types grow very quickly, maturing in five to eight weeks, and many are suitable for cut-and-come-again harvesting, so you can snip off a few leaves anytime you want a salad.
Lettuce is a cool season crop and is best grown in either spring or fall when temperatures do not go to extremes. However, even though lettuce likes to grow during cool, damp days, lettuce seed germinates best in temperature around 70 degrees Fahrenheit. This means you should start early-spring plantings in the garden with seedlings, rather than seed. If lettuce seed is put in the ground while it is still cold and wet, the seed will simply rot.
Even more than rich soil, salad greens need regular water. If the plants are allowed to remain dry for prolonged periods, especially in warm temperatures, they will turn bitter, the leaves may get sun scorched, and the plants will eventually go to seed. However, don't keep the area persistently damp or use mulch, which invites slugs.
Growing lettuce in soil that is rich in organic matter will give it most of the nutrients it needs. But it never hurts to supplement with an organic fertilizer like fish emulsion once every two weeks. Dilute the fish emulsion to half-strength, and apply it to the soil rather than the leaves.