With an array of beautiful colors and a variety of textures, lettuce has some of the widest ranges of selections within most of the vegetable crops grown today. We see lettuce all over our menus. Whether in a salad, an ingredient for sandwiches or even as a garnish for appetizers, lettuce has made its way into the lives of Louisianians.
Four different types of lettuce are grown in the world.
Days from planting to harvest can vary among the different types of lettuce. Leaf lettuce generally is harvested at 30 days and bibb lettuce at 30-55 days, while both romaine and crisphead lettuce generally require a longer interval of 60-65 days.
There are two seasons to plant and grow lettuce in Louisiana. Because it is a cool-season plant, gardeners get the best results planting lettuce in the fall and spring months. Fall lettuce can be planted anywhere between mid-September and the end of October, and a spring crop can be planted from the first of January through mid-March.
Gardeners should not plant lettuce during the long, hot days of summer because it can cause “bolting.” Bolting is the term used to describe the lettuce flowering cycle, which produces a physiological change inside the plant and affects its flavor.
Lettuce is typically started by direct seeding because it has a short germination period, and experienced gardeners know that the best variety selection can be obtained through the use of seeds. The seeds are extremely small. To help with the seeding process, many companies offer pelletized seeds that are coated in clay, making them easier to handle. Lettuce transplants are becoming more popular with retail nurseries and garden centers. Customers are able to start out with a small plant and get a jumpstart to harvest by eliminating the germination phase.
In-ground gardens, raised beds and container gardens all accommodate growing lettuce. A routine soil sample analysis will provide gardeners with the tools needed to maintain proper soil fertility. The optimal soil acidity or pH range for lettuce is between 6 and 7. This can be adjusted using agricultural lime or elemental soil sulfur if needed. The analysis will also quantify levels of phosphorous and potassium, which will influence the type of fertilizer needed.
Lettuce, like all other vegetable crops, has a few insect and disease pests that can be a problem during the growing season. Aphids, armyworms, cutworms, cucumber beetles and whiteflies are all known pests that attack lettuce. Some of the diseases that occur on lettuce include alternaria leaf spot, downy mildew and rhizoctonia bottom rot. To help discourage these pest issues, it is recommended to plant during the right time of year, follow proper plant spacing requirements and use recommended varieties.
Plant spacing will depend on type of harvest. Plant every 12 inches to grow out heads of lettuce or broadcast seed onto planting are to harvest baby greens. The use of mulch in the garden will provide a physical barrier between the soil and the plant. This will not only help with preventing disease organisms from coming into contact with the plant but also will help keep the plants clean from excess soil deposits.
More than 250 different varieties of lettuce are offered in popular catalogs. Look for varieties adapted for hot, humid climates of the South. Red Sails, New Red Fire and Salad Bowl are well-suited varieties of leaf lettuce. Some recommended varieties of romaine lettuce include Green Towers, Cimarron Red and Ideal. Skyphos, Harmony and Buttercrunch are excellent choices from the butterhead type.
For those looking to grow crisphead varieties, look for Raider and Ithaca.
William Afton is a county agent in St. Tammany Parish.
Salad Bowl. Photo by William Afton
Green Towers. Photo by William Afton
Skyphos. Photo by William Afton
New Red Fire. Photo by William Afton