Oak leaf lettuce (Lactus sativa var. crispa) is a form of leaf lettuce and, like it, belongs to the composite family (Compositae). Unlike lettuce, it does not form a head, but more or less loose leaf rosettes. Oak leaf lettuce can be harvested whole or leaf by leaf over a long period of time. Especially in the Netherlands and France, Oakleaf lettuce is a popular and frequently grown leafy vegetable.
Appearance and growth
Oak leaf lettuce owes its name to the curled bent leaves that stand in very large and spreading loose heads. They grow between 20 and 30 centimeters (8 and 12 inches) long and are yellowish-green, light green or reddish-brown, depending on the variety.
Location and soil
Sunny to semi-sunny locations in beds with loose, humus-rich and nutrient-rich soil are ideal for the plant.
Crop rotation and mixed cultivation
If the bed was previously planted with other composite plants, you should wait two to four years before growing Oakleaf lettuce there. Radishes, fennel, radish, spinach, and all cabbage vegetable species are good neighbors.
Starting in March, you can sow in trays or seed boxes in the greenhouse. Oak leaf lettuce will germinate after about one to two weeks at a soil temperature of 10 to 15 °C (50 to 59 °F). Then prick out the seedlings into potted trays. It is easier to direct sow outdoors from the beginning of April, depending on the weather. It is best to use rows with spacing of 25 centimeters (10 in). Separate the seedlings after emergence.
Planting Oak leaf lettuce
Seedlings, whether purchased or pre-grown, should be planted in the bed with adequate spacing. In the row it is necessary to maintain a distance of about 30 centimeters (12 inches), and the rows should also be spaced 25-30 centimeters (10-12inches) apart.
Care for Oak leaf lettuce
The lettuce should be watered sufficiently and regularly, especially in dry periods. Except for a compost application in spring, no further fertilization is necessary.
Diseases and pests
The toothed leaves and their reddish color tend to keep pests such as slugs away from Oak leaf lettuce. Aphids occasionally appear. Virus diseases can occur if plants are spaced too close together or have the wrong bed neighbors, although Oakleaf lettuce is basically relatively insensitive.
Harvest and use
Oak leaf lettuce is ready for harvesting just four to five weeks after sowing. You can harvest it one leaf at a time. If you leave the heart, new leaves will be formed. This extends the harvest time to about six weeks. The leaves can be prepared fresh, also gladly together with other leaf lettuces. Wash the lettuce just before preparing, so the leaves remain crisp. The taste of Oakleaf lettuce is somewhat spicy and nutty.