Romaine or cos lettuce (Lactuca sativa L. var. longifolia) is a variety of lettuce that grows in a tall head of sturdy dark green leaves with firm ribs down their centers. Unlike most lettuces, it is tolerant of heat.
Keep your lettuce plants consistently moist from planting until harvest. The ideal moisture will have your soil feeling like a wrung-out sponge.
Lettuce is generally considered to be a full-sun vegetable, and will germinate and grow more quickly if it's given as much daylight as possible. That said, it will tolerate partial shade and may even benefit from it during warmer weather.
Nitrogen-rich fertilizer promotes the leafy growth of butterhead lettuce. You can choose a single ingredient simple fertilizer such as blood meal, or feed by adding generous amounts of compost or manure to the soil. For a quick nutrient boost for successive plantings, use a liquid fertilizer formulated for vegetable gardens.
Prepare your planting bed by loosening the soil to at least 10 inches deep. Mix in an inch or so of good compost or well-rotted manure. Sow lettuce seeds a quarter of an inch deep and 1 inch apart in rows or squares, or simply broadcast them over the bed.
Unlike many vegetables, it’s almost impossible to harvest butterhead lettuce too early. The smallest leaves are tender and delicious as baby lettuce in salads. Make use of these leaves when thinning young plants in the garden. As the plants grow, you can harvest the outer leaves only, leaving the inner leaves to grow. Or, you can remove the entire plant if you desire a head of lettuce. By cutting the plant at the base and leaving the roots to grow, new leaves will sprout, giving butterhead lettuce a cut-and-come-again quality. It’s important to harvest butterhead lettuce before the plants bolt (produce flower stalks). The leaves of bolting plants become bitter and unpalatable. Butterhead lettuce is delicate and wilts quickly after harvest. Pick the leaves in the late morning when the dew has dried, or in the evening.
Temperatures between 65 (18 °C) to 75 F (23 °C) and nighttime temperatures between 50 t(10°C) to 60 F (15 °C).
Use ceramic pots that are porous which means your plants are less likely to experience root rot from overwatering.
