Lettuce Leaf Basil

Lettuce Leaf Basil is the gentle giant of the sweet basil family, named for its broad, deeply crinkled leaves that look and curl just like loose-leaf lettuce. Each leaf is soft, tender and unusually large, so a few are enough to flavour a whole dish. The aroma is a mellow, sweet blend of anise and clove — rounder and less peppery than common Genovese basil — which makes it a favourite for wrapping savoury bites, layering whole into salads and sandwiches, or tearing fresh over warm dishes just before serving. Its handsome, ruffled foliage also looks beautiful in pots and herb beds.

Planting

This is a warm-season annual that cannot tolerate frost. You can start seed indoors about 6 to 8 weeks before the last spring frost, or sow and transplant outdoors only once all danger of frost has passed and the soil has warmed; wait until nighttime temperatures stay reliably above 10 C before moving plants outside. Sow the seed shallowly, roughly 0.6 cm deep. Germination is best when the soil or media sits around 18 to 21 C, and seedlings usually emerge in about 5 to 10 days. Thin or transplant seedlings once they have formed 2 to 3 pairs of true leaves, setting them at their final spacing; indoor-started plants are typically ready to move out about 6 weeks after sowing once frost has passed. Space full-size plants roughly 15 to 30 cm apart, or 10 to 20 cm apart for closer cut-leaf production, with direct-sown rows about 45 cm apart. Choose a warm, sheltered, sunny spot, as basil needs full sun and at least 6 to 8 hours of bright light a day. In Egypt the main concern is cold nights below about 10 C rather than the summer heat: start seed in a protected seedbed in late January to February, then transplant out in March to April once nights are reliably above 10 C, for a long cutting season running roughly June through October. In the warmer south of the country the frost-free window is wider, so transplanting can begin a few weeks earlier in late February to March, and a second autumn crop is feasible. Avoid open-field sowing in the cold of mid-winter.

Fertilizing

Apply a low-nitrogen starter fertilizer before planting, such as a 5-10-5 or 5-10-10 blend worked into the bed. If growth slows about two months after planting, give the plants a nitrogen boost by side-dressing with calcium nitrate along each row section. Basil grown in good ground soil often needs no extra feeding at all. Plants in containers benefit from an organic-based balanced liquid feed diluted and applied every 3 to 6 weeks, while avoiding high-potassium feeds.

Care

Lettuce Leaf Basil is not drought tolerant and needs a fairly constant supply of soil moisture, so keep the soil evenly moist. Water deeply about every 7 to 10 days, and more often for plants in containers. Water at the base of the plant in the morning and avoid wetting the leaves, which helps reduce disease. Watch for common diseases such as downy mildew (fluffy growth on leaf undersides), Fusarium wilt, gray mold, bacterial leaf spot, and damping-off, along with pests including aphids, slugs and snails, spider mites, whiteflies, Japanese beetles and leafhoppers; watering at the base rather than over the leaves helps limit downy mildew. Pinch the terminal shoot tips at least once a week to keep the plant bushy, and harvest young leaves as you need them. For the best flavour, pick just before flowering and pinch out flower buds as they appear, since flowering turns the plant woody and makes the leaves more bitter with lower yield. For a full cut, take the plant back to about 10 to 15 cm above the ground to encourage fresh regrowth, and harvest in the cool of the early morning.