Leafy Salad Vegetables: Lettuce, Celery, Cress, Endive, Escarole, Chicory

by Bruce Johnstone.

Bruce Johnstone of Excelsior, Minn., retired as chief horticulturist at Northrup, King & Co. He co-authored Vegetable Gardening From the Ground Up, a paperback book, in 1976, and America's Most Beautiful Flowers in 1977.

The principal leafy salad vegetables covered in this chapter, especially lettuce, are among the most widely grown vegetables by home gardeners throughout the United States. Most of them but not celery and chicory are easy and fast to grow, and with the exception of celery are among the relatively few vegetables that tolerate moderate shade.

They also are adapted to small home gardens because each of them requires but little space for an average size crop. Salad crops in general also conform to the currently popular American taste for low calorie and high vitamin content foods.

Besides the leafy salad crops covered in this chapter lettuce, celery, cress, endive, escarole and chicory a few other leafy vegetables covered under different categories and in separate chapters also can be used advantageously as green leafy ingredients in salad making. Among these are spinach, New Zealand spinach, chard and mustard, each adding a slightly different flavor, color and texture to various salads.

Other common salad vegetables such as tomatoes, cucumbers, onions and radishes are covered in different chapters of this book and can be located through the table of contents or the index.

Lettuce

Known botanically as Lactuca sativa of the Composite family, lettuce probably originated somewhere in Asia Minor and the eastern Mediterranean region. Used as a food plant for some 2,500 years, it was a favorite of Persian kings in the sixth century B.C. and later as a food plant by the Romans. In the late 15th century, it first was brought to the New World by Columbus.

Lettuce seed is rather small (25,000 seeds per ounce), germinates quickly (7 days) in cool (65 -70 F) temperature, and produces a crop comparatively fast. Loose leaf lettuce types normally produce a crop in 40 to 50 days while most heading varieties require 60 to 80 days to mature.

The loose leaf varieties are more widely grown than heading types in home gardens because they are faster to mature, easier to grow, and somewhat more shade tolerant. They also have about three times as much vitamin A and roughly six times as much ascorbic acid or vitamin C as the equivalent amount of the heading varieties. Loose leaf varieties of lettuce require less thinning and thrive under somewhat warmer and more adverse conditions than the heading types.

Because lettuce basically is a cool weather crop, seed should be sown direct in the garden in early spring in order to mature before the summer heat arrives to cause bolting and deterioration of the foliage. (Bolting is premature flowering). Five feet of row per adult in family is usually enough for each planting.

Successive plantings can be made in midsummer for autumn crops. The seed should be scattered thinly, covered a quarter inch deep in rows as close as 8 and up to 24 inches apart, depending on space available.

Thinning is not absolutely necessary for loose leaf kinds but spacing the plants 4 to 6 inches apart is commonly recommended and results in larger, more easily harvested leaves. Typical loose leaf varieties available are: Black Seeded Simpson, Grand Rapids and Salad Bowl.

Heading varieties are of two main types, crisphead and butterhead. crisphead varieties are of thinner texture, are crisp, frequently have curled and serrated edges, are harder and more durable in handling and storage. Most of the so called Iceberg types available in stores are of this class. Other typical crisphead varieties: Ithaca, Great Lakes 118 and 659.

In contrast, butterhead types are softer and more fragile in texture, have thicker leaves and a smooth, buttery substance. Butterhead types Bibb, Buttercrunch, White Boston have a distinct delicate flavor and usually are more perishable than the crisphead varieties.

Heading varieties have cultural requirements similar to the loosehead types of lettuce except they require a longer, cooler growing season, more careful thinning, and need full sun for best development. All lettuce types are heavy feeders and because of their limited root structure require ample and constant soil moisture. They need high nitrogen fertility in a moist soil and give best results if growth continues unchecked.

Cos lettuce (Romaine) or celery lettuce has an elongated framework, smooth outer leaves, and a blanched inner head. The leaves are more brittle than the other heading types, the midrib is heavier, and the flavor uniquely sweet and mild. Cos types usually take 65 to 70 days to mature and have the same basic planting and cultural requirements as the other heading types. Most popular varieties are Paris White Cos and Paris Island Cos.

Where there are short, hot growing seasons as in much of our Northern, Central and Midwest states, the heading varieties are most successfully grown by starting seed indoors in very early spring, then getting the transplants into the garden as soon as frost danger is past. In this way the plants can mature and form heads before summer heat curtails growth and development.

Top, young gardener checks lettuce in her garden in Hawaii. Above, Bibb lettuce being harvested.

Harvest with a sharp knife as soon as looseleaf types are the size of your hand. Heading varieties should be full and firm. If allowed to go to seed in warm weather, leaves lose quality and become bitter.

When cultivating or hoeing lettuce, take care to keep the blade shallow and not too close to the plants to avoid injuring the root system which is sparse and close to the surface.

Homegrown lettuce is relatively free of disease although leafhoppers can be a problem, mostly in spreading virus disease. Effective chemical controls are available.