As Americans become more health conscious, we learn to value the wide variety of lettuce available fresh from the home garden. There are five main types of lettuce, each having an assortment of varieties and colors suitable for the home gardener: crisphead, butter head, leaf lettuce, cos or romaine lettuce and stem lettuce, also called asparagus lettuce. Leaf lettuce requires the least care and is the most commonly grown garden plant. The harvest starts with the thinning of extra seedlings and more leaves are close behind.
Prepare the soil in the spring as soon as the soil can be worked. Work in well-rotted manure or organic compost. Lettuce can grow in a wide range of soil types but prefer a slightly acidic soil with pH 6 to 6.5.
Plant lettuce in the spring when the average daily temperature is above 60 degrees F. Lettuce prefers cool weather and can survive a light frost. Choose a sunny location with loose, well-drained soil. Lettuce likes to be moist but not wet. Plant successive crops, about two weeks apart, through the spring. Plant again in the fall for a late crop as well.
Crisphead, butterhead and romaine can be started indoors about six weeks early and transplanted as soon as the soil can be worked in the spring.
Sow the seeds about a quarter to a half inch deep in single rows or wide broadcast rows. Thin the plants so that they are 4 to 6 inches apart for leaf lettuce, 6 to 10 inches apart for butterhead and romaine and 10 to 12 inches apart for crisphead plants. Use the thinned plants for your first fresh salad of the season.
Harden off transplants that have been started indoors or in a cold frame before planting. Move the plants outdoors for a few hours each day, extending the time outdoors each day until they are ready to be planted.
Water frequently to keep the plants moist and growing consistently, but do not overwater. Lettuce does not like to be wet. Mulch will help keep the soil moist and discourage weeds.
Weed lettuce carefully by hoeing shallowly or pulling weeds when they appear. Lettuce has shallow roots that aggressive hoeing or pulling mature weeds might damage.
Watch for aphids on the undersides of the leaves. Wash off aphids with a spray of soapy water and a blast of water. Remove slugs, snails or caterpillars immediately.
Harvest young and tender lettuce as soon as the plants are full size. Lettuce becomes bitter with age. Harvest leaf lettuce by removing the outside leaves and allowing the inner leaves to continue to grow.
Harvest butterhead and romaine lettuce like leaf lettuce, or cut the plant an inch above the soil surface. Allow the plant to sprout new leaves for a small second harvest.
Cut crisphead lettuce when the head is firm.