If you grow only one vegetable other than tomatoes, it should be lettuce. Growing lettuce is so easy, takes up little space, and you can even grow it among flowers and herbs. We often use it as a living mulch around the tomatoes in the early spring. Lettuce grows for many weeks in the mild weather of spring and fall. Leaf lettuce is easy to tuck in between and under taller vegetables and is perfect for containers. In this article, I’ll cover how to plant, grow, and harvest lettuce.
BEST SOIL FOR GROWING LETTUCE
Although lettuce grows fastest in full sun, it is one of the few vegetables that tolerates some shade. In fact, a spring crop often lasts longer if shaded from the afternoon sun as the season warms. You can grow lots of lettuce in a small space, even a container. Mix it with other taller plants, such as tomatoes in the spring, or grow a mix of different varieties for a living salad bowl.
Give lettuce fertile, well-drained, moist soil with plenty of rich organic matter and a pH between 6.0 and 7.0. To check pH, test the soil with a purchased kit, or get a soil test through your regional Cooperative Extension office. Fertilize and lime according to test recommendations.
Lettuce plants adapt to their spacing. For largest plants, space at the maximum distance given on the label.
In the spring, begin setting out lettuce plants about a month before the last frost. Lettuce grows best within a temperature range from 45 to about 80 degrees. Hot weather makes it bitter; extreme cold freezes it. When well rooted, some Bibb types such as Buttercrunch will tolerate a surprising amount of frost.
Plant fall lettuce beginning about 4 to 8 weeks before the first frost. If you use a cold frame or row cover, gardeners in many areas of the country can grow lettuce through the winter.
Lettuce spacing is not an exact science, but most varieties tend to do best with spacing between 6 and 18 inches (depending on the type, so check the seed envelope or tag). Generally, you should space plants far enough apart so that they can grow to full size. However, many gardeners plant lettuce much closer together, preferring to harvest leaves continuously before they reach full size. This is what Scott and I so. The plants adapt to their spacing.
CARING FOR LETTUCE
For the most tender, succulent leaves, water regularly during dry weather. Also, mulch to keep the soil cool and moist, and prevent weeds.
The most common lettuce pests are aphids. They love the tender leaves and like to hide on the undersides and down in the crown of the plants. Keep an eye on your plants and if you notice any aphids, blast them with water to prevent an infestation. In the springtime ladybugs and ladybug larva will usually keep aphids in check if you have an organic garden.
HARVEST AND STORAGE
You can harvest leaf lettuce from the outside of the plant, leaving the central bud to grow more leaves, or you can cut the entire plant at the base. Leaf lettuce is ready to eat at just about any size, and you can pick the baby leaves for tender salads. Romaine lettuce forms its characteristic mid-rib before harvest; at full size, it makes an upright leafy clump. Bibb types such as Buttercrunch form a loose head; you can harvest anytime, but for the classic Bibb rosette, wait until the lettuce is nearly full size (6 to 8 inches in diameter) and cut it at the soil line.
The same is true for heading iceberg types; however, in warm climates where head lettuce doesn’t make a firm head, you can harvest it like leaf lettuce, removing leaves as they get large enough to eat.
Lettuce tastes sweetest in cool weather, which is why it is such a great fall crop. As the weather warms, plants will go to seed. By the time they begin to stretch and send out a seed stalk (called bolting), the leaves are bitter. When this starts to happen, harvest all your lettuce immediately and try storing it in the refrigerator, where some of the bitterness may disappear.