Romaine Lettuce Growing Stages

Planting

• The planting stage occurs when you plant the seeds in the soil where you expect the plant to grow. For best results, plant the seeds in loose, sandy loam soils with good drainage. Organic matter introduced into the soil, such as mulch and compost, aerates the soil and gives it a boost for healthy growth. Seeds should be planted between 1/2 and 1 inch into the soil.

Germination

• It takes between five and seven days for Romaine lettuce seeds to sprout, if watered properly. A number of variables dictate the seeds' watering needs. If planted in late winter on the central California coast, seeds need only two to three days of water. In hot and dry conditions, however, the seeds must be watered every day, otherwise they will not germinate. All lettuce varieties prefer cool weather and tolerate light frost, but temperatures between 45 and 65 degrees Fahrenheit are ideal.

Seedling

• The seedling stage occurs after the seed germinates, and it lasts between one to two weeks. This is the phase where the sprout begins to develop and the plant is at its most delicate stage. The first leaves begin to form and the root system starts to develop. During this stage, it is important that the soil be kept moist but well drained. Romaine has deeper root systems than leaf lettuce varieties, and it needs ample room and moisture for healthy development.

Vegetative Stage

• After the seedling develops it first "true" leaves, the vegetative state begins. This lasts about 30 to 45 days, depending on weather, soil and water conditions. The root system expands and the romaine plant unfurls its mature leaves. Unlike iceberg lettuce, romaine lettuce grows upright and not into a ball. Lower night temperatures encourage a better leaf mass, making the lettuce crispier and more palatable. Romaine lettuce can be harvested by pulling off the outer leaves, leaving the plant alive in the soil, or by cutting out the whole head.

Bolting, Flowering and Ripening Stage

• When a lettuce passes the mature vegetative state, it enters the bolting stage. During this time, the plant chemistry changes and the leaves become bitter to the taste. This period lasts another 30 days, with the central stem growing tall. The bolting stage occurs in preparation of the flowering stage. After the bolting stage is complete, small flowers bloom that resemble small daisies or dandelions. The flowering stage lasts another three to four weeks. The flowers open in the morning and close at night. Seeds begin to ripen about 11 to 13 days after the flowers first bloom and continue ripening until the flowers die. At this time, the lettuce is no longer edible and should be disposed of after the seeds are collected.