Home garden lettuce

NC STATE UNIVERSITY Horticulture Information Leaflet 8011 Revised 1/01 - Author Reviewed 1/01 College of Agriculture & Life Sciences Department of Horticultural Science HOME GARDEN LETTUCE Douglas C. Sanders, Extension Horticultural Specialist I Head lettuce is the most important salad vegetable grown in the United States. Per- capita consumption exceeds 25 lb annually. Lettuce is adapted to cool growing conditions with the optimum temperatures for growth of 60 to 65°F. At 70 to 80°F the plants flower and produce seed. Lettuce can tolerate a few days of temperatures from 80 to 85°F provided nights are cool. Lettuce seed will germinate at 35°F, but optimum germination is 70 to 75°F. If the plants are sufficiently hardened, they will withstand freezing. Repeated exposure to subfreezing temperatures, however, can seriously injure or kill the crop. Lettuce has a relatively high water requirement. Soil moisture shortage rainfall will seriously stunt growth and head quality. Irrigation greatly reduces risk of crop failure. There are considerable differences among lettuce varieties in heat tolerance. These differences are the primary reasons some lettuce varieties can be grown in warmer climates. Distributed in furtherance In North Carolina, the crop can be grown in O. Ma°/“n°ef ToTu. both the spring and fall in eastern N.C. and Employment and program even during midsummer in western N.C. at opportunities are ottered to aii people regardless of elevations over 3,000 ft. In the Piedmont, race, color, national oriqin, , ,, ■ ■ , . ■ , , , , sex, age, or disability. North lettuce is intermediate in season and probably Carolina State University, js best as a |ate spring and early fall Crop. North Carolina A&T State Г to J г University, U.S. Department ot Agriculture, and local governments cooperating. STATE UNIVERSITY A&T STATE UNIVERSITY COOPERATIVE EXTENSION Helping People Put Knowledge to Work Romaine has requirements similar to head lettuce except it can stand more heat. Butterhead and leaf types can stand even more heat and have a longer season of production. Varieties — Request mosaic-tested (M.T.) seed from your seed supplier. • Head: Strains of Ithaca, Salinas and Pennlake have performed best in N.C. • Romaine/Cos: Romulus or Signal • Leaf: (green) Salad Bowl, Slobolt, Grand Rapids, Green Vision; (red fringe) Red Sails, Royal Red; (red) Ruby. • Butterhead : (loose head) Buttercrunch, Nancy (a.k.a. Boston head), Esmeralda, Ermosa. Soils and Fertilizers — Successful production of lettuce depends on vigorous growth. A wide range of well-drained soils can be used; however, the crop does best on fertile, high organic matter soils that have good water-holding capacity. Adequate nutrients and a continuous moisture supply are essential to vigorous growth. A soil test is the only way of knowing the amount of lime and fertilizer required, and soil samples should be taken well ahead of field preparation. Your county Extension center can advise you in having your soil analyzed.