Not just for Caesar salads, romaine lettuce, also known cos lettuce, is an excellent choice of greens for your garden. These plants will develop narrow, upright, long leaves with a well-defined central rib. The leaves will bunch up into the familiar elongated head shape when the plant reaches maturity. The taste is slightly bitter, but delicious, with inner leaves being lighter in color and milder in flavor. Most varieties of this type have some heat and/or disease tolerance. Successive plantings every 2 weeks will give you plenty of salad greens throughout the season.
The Little Gem varietal of romaine truly lives up to its name as an easy-to-grow and extremely sweet type of lettuce. The heads of this varietal are smaller than most others and only grow to about 6″ in height; however, what they lack in size they certainly make up for in flavor and crispness. The little leaves have a wrinkled texture and light green hue that make them pleasing to the eye in salads or as an edible plate garnish. Little Gem is also quite tolerant of heat and requires less space than its larger-leaved relatives, making it a real garden jewel.
Seed Depth: 1/8–1/4″
Space Between Plants: 8–10″
Space Between Rows: 6–8″
Germination Soil Temperature: 50–70°F
Days for Germination: 7–14
Sow Indoors: 4–6 weeks before average last frost date.
Sow Outdoors: 2–4 weeks before average last frost date. Plant successively every 3 weeks until 6 weeks before average first frost date. For a winter crop in warm climates, plant 2–4 weeks before average first frost date.
Grows best in cool weather and will survive mild frosts. Even the more heat-tolerant variety of Little Gem will bolt in extreme heat, and germination will be poor in temperatures above 80°F. We recommend planting when temperatures are still moderate (i.e., in the early spring in moderate climate zones and late summer/early fall in hot climates).
Natural: Full Sun. Prefers partial afternoon shade in warm weather.
Artificial: Grows well under fluorescent or LED lamps. Needs at least 12 hours of light daily; however, more is preferred. A 24-hour day cycle may result in highest yields.
Soil: Prefers loamy soils with a high amount of organic matter but are adaptable and will grow in most soil types. A pH between 6.0 and 6.8 will keep plants healthy and nourished.
Soilless: Seeds will germinate in soilless mixes, rockwool, and other soilless media.
Hydroponics: Will thrive in hydroponic systems including NFT, floating raft technique, or deep water culture.
Aeroponics: Will thrive in aeroponic systems.
Water: Requires moderate levels of water. Although this lettuce does not require a large quantity of water, it does require consistent watering. Ensure that soil is moist but not muddy.
Nutrients: Requires moderate to high levels of nutrients. Nitrogen-rich fertilizers such as blood meal will help lettuce plants grow full and succulent leaves. Potassium and phosphorus levels need to be adequate for good growth, as well.
Foliar: Application of foliar sprays containing nitrogen will keep plants healthy and strong.
Mulching: Mulch may be used around the plant to keep weeds down and protect the plants’ shallow root system from damage or competition.
Deficiency(s): A lack of phosphorous, potassium, and, most commonly, nitrogen can cause plants to wilt or be stunted in growth.
Rotation: Follow with a legume crop, like peas or beans, to replenish soil nitrogen levels.
Companions: Grows well with carrots, collards, onions, strawberries, beets, cucumber, brassicas, radishes, marigold, borage, chervil, florence fennel, and leeks. Avoid parsley and celery.
Harvest: Harvest your lettuce when the head has grown 4–6″ tall, with tight leaves and a firm, but not too hard, texture. Cut just above soil line and leave the roots in place to allow your plant to grow more leaves, if desired. You can also pick individual leaves from the outer edges of the plant earlier, but don’t take more than 1/3 of the total plant. Try to harvest in the morning when leaves are moist and cool.
Storage: Store in the refrigerator for up to 1 week. Avoid storing lettuce in the same area as fruits such as bananas or apples: they release a ripening agent that causes your lettuce to go bad more quickly.
History: The lettuce plant had a strong foothold in Egyptian culture and was harvested for seed oil as well as its crispy leaves. Lettuce was also considered a symbol of the god, Min, who was associated with fertility and reproduction as lettuce was considered to be an aphrodisiac by the Egyptian people.
Preserve: Due to its high water content, lettuce cannot be easily preserved and should be eaten fresh.
Prepare: Good for use in salads, sandwiches, smoothies, or even soups. Chop off the bottom of heads and separate individual leaves. Wash just before using for longest storage life.
Nutritional: A good source of vitamin(s) A, K, calcium, potassium, and manganese. Also contains good amounts of dietary fiber.
Medicinal: Historically, lettuce was cited as a veritable cure-all. Today, it has been shown to have high levels of beta-carotene. The antioxidant content of darker leaves may offer some protective benefits against disease.