University of Illinois Extension

Try Several Kinds of Lettuce

Whether you are seeking lush, interesting foliage in the garden or a stylishly delicious salad on your table, there are many varieties of lettuce to delight you, said Barbara Bates, Extension horticulture educator.

“There are more kinds of lettuce than there are purple petunias,” said Bates. “And they are just about as easy to grow. As an edible ornamental, lettuces are hard to beat when you consider their versatility in the garden and in the kitchen.”

Lettuces come in a wide variety of colors, textures, and flavors making them useful as garnishes, as a bed for other foods, for creative salads, and for sandwich wraps.

“They perform well when grown in vegetable gardens and they can be effortlessly integrated into borders of flowers and ground covers,” she said. “When used in containers, they act as fillers to highlight blooming plants or as a focal point depending on the variety you choose.

“Lettuces mature quickly and can be successively seeded for season-long delicious eating. If you like a formal look, plant them in regimented rows or, for an informal look and higher yields, scatter the seed in a broadcast style.”

Bates said that lettuces are grouped into four types based on their growth habits. The four main growth habits are leaf, head, butterhead, and romaine.

Leaf lettuces may be broad or narrow. They can be ruffled, flat, or lobed as with oak leaf types.

Head lettuces form tight, crisp heads that are self-blanching so the interior leaves remain pale. Butterhead lettuces form smaller, looser heads with a flush of exterior leaves that are more substantial in texture. Romaine varieties have upright leaves in a tight cluster with thick fleshy midribs. Foliage for all types comes in shades of green and burgundy red, or they can be speckled.

“Lettuce is a cool season crop, preferring daily temperatures between 60 and 70 degrees Fahrenheit,” said Bates. “While most varieties prefer cool weather, there are some that perform better in warm weather without developing a bitter taste or bolting to form seed heads. Varieties with good heat tolerance are referred to as summer lettuces.”

Varieties that perform well in warm weather include ‘Optima’, a deep green butterhead type; ‘Little Gem’, a deep green romaine variety; ‘Buttercrunch’, a compact head type; ‘Summertime’, a head variety frilled with outer leaves; ‘Tom Thumb’, a compact butterhead type; and ‘Capistrano’, a romaine variety excellent for harvesting in late summer.

Outstanding varieties for flavor include ‘Nevada’, which has a nutty flavor, while ‘Speckles’ and ‘Esmeralda’ are both described as having a buttery flavor. ‘Little Leprechaun’ is sweet and crisp. An old-time favorite is ‘Salad Bowl’ because of its wonderful mellow flavor.

“If it is visual interest you want--along with fresh produce, try ‘Oakey Red Splash’, ‘Merlot’, ‘Green Deer Tongue’, and ‘Devil’s Tongue’,” said Bates. “The variety ‘Outredgeous’ is a ruffled red lead type which gets as big as a bushel basket.”

Several methods for harvesting lettuce are available, depending upon growth habit and planting method. Harvest can begin as early as three weeks after planting by thinning young plants when they reach three to four inches in height.

“Most leaf lettuces reach full maturity in 50 to 60 days,” she noted. “As leafy types mature, a ‘cut and come again’ method of harvest is used. With scissors or a knife, cut at least one inch above the soil, removing all the leaves as you harvest. The crown will grow new leaves for a second harvest.

“With head-forming types, harvest first by thinning them by removing the entire head.”
Prior to sowing, make sure the soil has sufficient organic matter to allow for moisture penetration and retention. Frequent, shallow watering works best to encourage good growth. Soil moisture is critical to lettuces, because they are shallow-rooted, and careful attention should be paid when cultivating around plants to avoid damaging roots.

“Leafy crops such as spinach, greens, and lettuce are ‘heavy feeders,’ meaning they respond to applications of nitrogen by producing more and larger leaves,” she said. “Mix a balanced fertilizer--such as 10-10-10--in the soil prior to planting.

“Follow that with a side dressing of a fertilizer high in nitrogen--such as 30-10-10--when the plants have three to four true leaves.”