No other salad crop is grown or used in such large quantities as lettuce, which has become an essential part of salads. Lettuce is a cool-weather crop that can be grown in spring or fall. Hot weather causes it to become bitter and to develop a tall seed stalk.
• More detailed information can be found in The Georgia Fruit & Vegetable Book by Walter Reeves and Felder Rushing
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The iceberg lettuce commonly found in grocery stores is head lettuce grown in the South in the winter and in the cooler parts of the country during the summer. Leaf, romaine, and butterhead or Bibb lettuce often are grown in greenhouses and are more common in home gardens.
WHEN TO PLANT
Lettuce can stand a freeze. Plant it early and harvest it before hot weather arrives. For the earliest production, start with transplants, either homegrown or from garden centers. To grow your own, sow the earliest seed for head lettuce indoors about 8 weeks before the frost-free date (average date of last frost), and sow seed for leaf lettuce indoors 2 weeks later. Grow the plants under lights or in the greenhouse, and transplant them into the garden when they are large enough to handle-about 3 or 4 weeks before the frost-free date. Transplants are usually available from garden centers about that time as well; buy plants that have a good green color, are short and compact, and have no pests. Unless you want lots of lettuce at one time, make several seedings to spread out the harvest. Lettuce seed needs light to germinate, so do not cover it. Sow seed of leaf lettuce varieties directly in the garden as early as the soil can be worked. Spring-planted lettuce will be harvested and out of the garden by early summer, but you can begin planting again in August and September; with successive seed sowing (every two or three weeks), you can harvest fresh lettuce well into the New Year.
WHERE TO PLANT
Lettuce prefers full sun (8 to 10 hours will suffice), but to have extended production during the hot summer months, plant it in partial shade (filtered sun all day or shade part of the day). Excellent drainage is beneficial for these plants need lots of water for vigorous growth. The roots cannot stand soggy soils, however; plants in soggy soils will be susceptible to diseases, and leaves may scald (dry out and become papery) at the edges. Lettuce also grows very well in containers, even on porches and patios, but more attention will be needed to watering and fertilizing.
HOW TO PLANT
Apply a complete garden fertilizer, such as 10-10-10, at a rate of 11/2 pounds per 100 square feet of garden. Spade or rototill the soil. (See “Soil Preparation” in the introduction to the vegetable garden.) In rows, space the transplants of head lettuce about 12 inches apart, with 12 to 18 inches between rows. In a bed, space the plants of head lettuce 12 inches apart, which will allow 3 or 4 heads across the bed. Set transplants at 4 by 6 inches for leaf types, or 6 by 6 inches for Bibb or romaine types. Set the plants at the same depth they were growing. Seed leaf lettuce in triple rows (3 closely spaced rows in a row) 12 inches apart. Thin leaf lettuce to 4 inches and Bibb or romaine types to 6 inches. In beds, sow rows 6 inches apart, then thin to 4 to 6 inches between plants.
CARE AND MAINTENANCE
To keep the plants growing, water them as needed, about 1 inch of water per week. Control weeds while the plants are small by careful hoeing or pulling. Be careful; lettuce plants are shallowly rooted and easily uprooted. Pests may affect the plantings. Control insects by keeping the plants well spaced and harvested as they mature. Control aphids by spraying undersides of leaves with insecticidal soap, then rinse the foliage to remove the residue. (See the pest control chart in the introduction to the vegetable garden.)
Harvest leaf lettuce by snipping off the outer leaves as soon as they are large enough for your use. When plants are large enough, harvest every other one, leaving more room for the others. Harvest head, bibb, and romaine lettuce when the heads are full size. Mesclun is a mixture of many kinds of leaf lettuce and some other salad greens (such as escarole, arugula, cress, and endive) broadcast-sown together and harvested by snipping leaves of each kind as they mature. It makes an interesting salad. A problem with lettuce picked in hot weather is that it will be bitter. Wash it and store it in the refrigerator for a couple of days, and it will lose the bitterness.
Four types of lettuce are grown in gardens. Bibb lettuce forms small, loose heads and has a mild, buttery flavor. Head lettuce is the kind available year-round in supermarkets; it is not heat tolerant. Leaf lettuce may be either green or red. Various leaf forms are grown; some are smooth and round, and others are deeply cut, wrinkled, serrated, or curled. Romaine lettuce forms loose, upright bunches; outer leaves are green while the interior leaves are blanched and white.
Days to Maturity
50 to 60 days
Tolerates high temperatures. AAS.
Dark Green Boston
50 to 60 days
Large heads, grown commercially.
50 to 60 days
Holds well in heat; does not bolt.
50 to 60 days
Tender, miniature heads.
Tolerates warm weather.
Standard head lettuce type commonly available in food stores.
Slow to bolt.
Leaf Lettuce, Green:
Early Curled Simpson
For fall crop.
Good in hot weather.
Leaf Lettuce, Red:
Slow bolting. AAS.
Red Salad Bowl
Deeply cut burgundy.
Parris Island Cos
Slow to bolt.