Lettuce is the “green” most of us are comfortable eating with some regularity, and consumption is still dominated by that old standby: iceberg lettuce. Iceberg lettuce is a relative newcomer, introduced during the late 19th century. The first known cultivars of heirloom lettuce varieties were probably the looser head types like romaine, grown in Egypt as early as 4500 B.C.
Lettuce (Lactuca sativa) is derived from the wild plant Lactuca serriola, a coarse annual or biennial native to Europe and found worldwide, possessing vague resemblance to the domesticated forms we commonly eat. It is a member of the sunflower or composite family.
While technically edible, heirloom lettuce has prickly leaves and sap concentrations that make it relatively unpalatable, especially uncooked. When cooked, all but the youngest plants need two changes of water. Several native species from North America are similar and edible. Personally, I’d stick with the garden type; yet, hunter-gatherers foraged for wild lettuce plants until ancient Greek times. Early man had a considerably higher tolerance for bitterness than we do, although many people still like that taste in “hoppy” ale.
Lettuce comes in a variety of forms. The main types of lettuce are loose-leaf varieties, not forming a true head; butterhead or cabbage with very loose heads and soft yellow-green leaves characterized by the small Bibb and later big-headed Boston lettuce, a 19th-century introduction; cos or romaine, generally forming loose upright heads; heading lettuce, forming true solid heads, particularly iceberg; and stem lettuce, otherwise known as celtuce, with a long edible stem and leafy top.
Lettuce’s long history
An Egyptian wall fragment from the third millennium B.C. portrays Min, the god of fertility, in what appears to be a field of lettuces identifiably romaine. Cos, the alternative name used for romaine lettuces, comes from the Greek Island of Kos, which was cultivation center in the Byzantine era. Lettuce was consumed throughout the Arab world and was used medicinally with vinegar for the stomach in the Byzantine Empire of the 11th century.
Cos lettuce traveled to Italy in Roman times where it was consumed raw as an appetizer — still a culinary practice today — or cooked and served with oil and vinegar. It arrived in France by the 15th century where it was christened Avignon lettuce in the 1530s and later became known as Roman (hence Romaine) lettuce. By the late 16th century loose-leaf and heading types were known.
At other times in its history it has been used to cool the body, as a sedative narcotic, as an anti-diarrheal, and to reduce coughs. It was used as a medicinal herb in medieval times. Recently a product obtained from the sap of lettuce variously referred to as “lettuce opium” or “hash” has gained limited popularity as an underground drug.
The leafier varieties of lettuce have been gaining turf during the last couple of decades. Per capita, consumption was up to 11 pounds in 2009, while iceberg consumption decreased to around 17 pounds per person. This makes a grand total of 28 pounds per year, or about 1/2 pound per person per week. This uptick is partly due to various forms of salad mixes being widely consumed, and I suspect renewed interest in eating well plus some disaffection with the bland taste of iceberg lettuce.
Available heirloom lettuce varieties
The world of heirloom lettuce offers many interesting varieties still available from a wide array of sources. I’ll cover just a handful now. Lettuce is largely a self-pollinating plant, which means when separated by a short distance, typically 20 feet, the odds of cross pollination is generally less than 1 percent. Even more closely spaced plantings probably will be fine, and it never hurts to allow more room. Be aware, however, that it can cross. Lettuce seed remains viable for several years — up to about five — without special storage conditions, and then germination rates drop off rapidly. This ability to self-pollinate and remain relatively stable is perhaps part of the reason many heirloom varieties have survived.
One of the most well-known varieties is Forellenschluss, a loose-headed romaine that can grow 12 to 16 inches or more across, with wine-red speckles and splotches overlaid on medium green leaves. This is an Austrian variety, originally preserved by Arche Noah, an Austrian seed preservation organization. In German, Forellenschluss means “speckled like a trout” or Trout’s Back. Speckled romaines or cos were known from England in the 17th century. Another variety known as Spotted Aleppo or Spotted Cos has less vivid, bronzy red speckles. Aleppo originated in Syria prior to its introduction to Europe as early as the 17th century. It is listed in Philadelphian seedsman Bernard McMahon’s 1804 broadside catalog. The outer leaves of many romaines may be gathered together and tied, which both helps in the formation of the head and blanching the inner leaves.
Merveille des Quatre Saisons, or Red Besson, is a butterhead type lettuce with red-tinged crinkled leaves forming a soft, loose, light green head, and listed by Vilmorin in 1885 as the most “highly colored of all the Lettuces grown about Paris.” The name means “Marvel of Four Seasons,” and it does fairly well in cold temperatures, though less well in heat.
Black Seeded Simpson is another one of the great loose-leaf lettuces that has never gone out of fashion and is easily available. It quickly forms substantial, leafy, light yellow-green ruffled plants that if planted too close together can rot at the base because of the abundance of foliage. It was introduced in 1870 by Peter Henderson of New York.
Growing the best lettuce
Lettuce can be planted from seed as soon as the ground has warmed. While lettuce will grow in almost any soil, it really prefers cool, fertile soil that is kept well-watered. Direct sowing works best only for the loose-head varieties, especially when used for cutting as opposed to whole-plant harvest. The ideal method is to sow lettuce seeds in flats with individual compartments. This minimizes seed waste and allows you to maintain ideal spacing. Transplant after five or more leaves have appeared. Make sure plants are well-watered in the flats before transplanting and in the garden after planting. Large transplanted seedlings exposed to heat with less than optimum moisture conditions will wilt. While they will recover, often those first big leaves will die, slowing the plants’ growth.
While seed packets often recommend planting 6 to 12 inches apart, 12 to 15 inches is useful for developing large heads of the big varieties. Direct sowing of the heading varieties is often a waste of effort unless one is rigorous about thinning plants when they only have a few leaves. Otherwise the plants quickly get crowded and tend to bolt much sooner without forming heads or being very productive.
For most locations, lettuce does best in the spring and fall, and it can be grown throughout the summer if the temperature is not too extreme. Plants can be more resistant to bolting in a cooler maritime or mountain location and with good, rich soil. Heat is not the only factor that causes bolting. Lettuce’s exposure to longer days is a primary reason that bolting occurs in the summer. Some varieties are more bolt-resistant than others.
Ethnobotanist Lawrence Davis-Hollander gardens, cooks, and — at a nearby preserve — watches bald eagles and spring wildflowers.