Romaine Lettuce

TL;DR: Romaine is a sturdy, heat-tolerant cool-season lettuce best planted in spring or fall, either started indoors 6 weeks before the last frost or direct-sown ½" deep, spaced 8-12" apart. Use succession planting every 2 weeks for a continuous harvest. Keep soil consistently moist with light watering and mulch to prevent bolting, and watch for slugs and snails. Harvest outer leaves as needed, or cut the whole head at 60-70 days about 1" above the soil for a possible second flush. Nutritionally, it's the most dense of common lettuces, rich in vitamins A and K, folate, potassium, and calcium.

Romaine lettuce, also known as Cos lettuce, is a garden favorite prized for its sturdy, upright growth and the satisfying crunch of its thick midribs. Unlike many delicate leaf lettuces, Romaine is remarkably heat-tolerant and holds its shape well, making it the essential base for Caesar salads and a crunchy addition to sandwiches. Its long, spoon-shaped leaves grow in a tight head that transitions from a deep green on the outside to a pale, succulent heart in the center. Because it is a cool-season crop, it performs best during the moderate temperatures of spring and autumn, offering a crisp sweetness that store-bought heads often lack. Planting Romaine is a flexible process that can begin as soon as the soil can be worked in the early spring. For an early start, you can sow seeds indoors six weeks before the last frost, or simply direct-sow them into the garden about half an inch deep. Because the seeds are tiny and require a bit of light to germinate, you should cover them only lightly with a fine layer of soil. Space the plants about 8 to 12 inches apart to allow the heads to expand fully. To ensure a steady supply of greens throughout the season, try "succession planting" by sowing a new row every two weeks until the weather turns hot. Maintaining your Romaine patch is all about keeping the plants cool and hydrated. Lettuce has shallow roots, so it requires frequent, light watering to prevent the soil from drying out; if the plant becomes stressed by thirst or extreme heat, it may "bolt" (go to seed) and become unpleasantly bitter. A layer of organic mulch around the base of the heads can work wonders for retaining soil moisture and keeping the roots at a comfortable temperature. While lettuce is generally easy to grow, keep an eye out for slugs and snails, which can be managed with organic bait or simply by hand-picking them during the damp early morning hours. Harvesting Romaine offers two wonderful options: you can harvest individual outer leaves as soon as they are large enough to eat, or you can wait for the entire head to reach full maturity, which usually takes about 60 to 70 days. To harvest the whole head, simply cut it off about an inch above the soil line with a sharp knife; if you’re lucky, the remaining stump may even sprout a second, smaller "bonus" harvest! Beyond its delightful texture, Romaine is the most nutritionally dense of the common lettuces. It is a fantastic source of Vitamin A, Vitamin K, and folate, as well as minerals like potassium and calcium, making it a refreshing way to support your heart health and immune system.