Romaine Lettuce

Start romaine lettuce seeds indoors 4-6 weeks before last frost, sowing on the soil surface or barely covered (seeds need light to germinate). Seeds germinate in 4-10 days at 55-70°F. Transplant hardened-off seedlings 10-12 inches apart in rows 12-18 inches apart. Direct sowing is also effective, scattering seeds thinly and thinning to proper spacing.

Romaine lettuce grows best in cool weather between 55-70°F but is more heat-tolerant than many lettuce types. Provide consistent moisture to maintain crisp leaf texture. In warm weather, provide afternoon shade with taller plants or shade cloth to delay bolting. Mulch around plants to keep roots cool and retain moisture. A light feeding with balanced fertilizer every 3-4 weeks supports steady growth.

Succession plant every 2-3 weeks from early spring through fall for continuous harvest. For the best quality heads, harvest in the morning when leaves are most turgid. Romaine can be grown as a cut-and-come-again crop by harvesting outer leaves, or left to form full heads over 55-70 days. In mild climates, romaine can be grown through the winter with minimal protection.

Lettuce cultivation traces back over 4,500 years to ancient Egypt, where tall, romaine-like varieties were first grown not for food but for the oil extracted from their seeds. Wall paintings in Egyptian tombs depict lettuce remarkably similar to modern romaine, with its characteristic upright, elongated form. The plant was sacred to Min, the Egyptian god of fertility and harvest.

From Egypt, lettuce cultivation spread to ancient Greece and Rome, where it became a staple table vegetable. The Romans are credited with developing the cos-type lettuce (another name for romaine, from the Greek island of Cos where a popular variety grew). Roman emperors reportedly served it at banquets both as an appetizer to stimulate appetite and as a post-meal digestive aid. The Roman naturalist Pliny the Elder documented multiple lettuce varieties in his writings around 79 AD.

Romaine lettuce arrived in France via papal gardens in Avignon during the 14th century, where it became known as 'laitue romaine' — Roman lettuce — giving it the name used worldwide today. From France, it spread across Europe and eventually to the Americas with early colonists. In the 20th century, romaine's popularity surged with the rise of the Caesar salad, invented in Tijuana, Mexico in 1924 by Italian-American restaurateur Caesar Cardini. Today, romaine is the second most popular lettuce type in the United States and remains essential to Mediterranean, Middle Eastern, and Asian cuisines.

Romaine lettuce thrives in fertile, well-drained soil with a pH of 6.0-7.0. Amend with compost before planting for moisture retention and fertility. Apply a balanced fertilizer at planting and side-dress lightly every 3-4 weeks. Avoid excessive nitrogen, which produces lush but bitter-tasting growth susceptible to disease. Lettuce has shallow roots, so consistent surface moisture is more important than deep watering. Organic mulch helps maintain the cool, moist conditions lettuce prefers.

Harvest romaine lettuce as baby leaves starting at 25-30 days, or wait 55-70 days for full heads. For cut-and-come-again harvest, pick outer leaves when they reach 6-8 inches, leaving the inner growth to continue. For full heads, cut at the base when the head feels firm and upright. Harvest in the early morning for maximum crispness. If the center starts to elongate upward, the plant is beginning to bolt; harvest immediately as flavor turns bitter after bolting.

Store whole heads or loose leaves in a plastic bag in the refrigerator crisper for 7-10 days. Romaine stores longer than most lettuce types due to its sturdy leaves. Wrap heads in damp paper towels for extended freshness. Lettuce does not freeze or dry well. For maximum shelf life, do not wash until ready to use. Romaine hearts (with outer leaves removed) keep particularly well. Revive slightly wilted leaves by soaking in ice water for 15-30 minutes.

Romaine is the essential lettuce for Caesar salad, providing the ideal crisp, sturdy base. Grill halved romaine hearts for a smoky charred salad. Use leaves as wraps for tacos, burgers, or lettuce cups. Chop for green salads, wedge salads, or add to sandwiches and wraps. The sturdy leaves hold up well to heavier dressings. Hearts can be braised in broth for a warm French-style side dish.