Lettuces (Lactuca)

The world of salads is varied and colorful. With a wide variety of leaf shapes, colors and subtle nuances of flavor, salads can be used in lots of ways in the kitchen. The Lactuca family of lettuces contains the well-known spring and summer head-forming lettuces: Butterhead lettuce, Batavia lettuce, iceberg lettuce, romaine lettuce as well as cut lettuces and cut-and-come-again salads. Lactuca lettuces are members of Asteraceae family.

In lettuce breeding, Sativa focuses on modern, bolt-resistant butterhead and Batavia lettuces with good resistance against powdery mildew. In the unique joint project “Mit vereinten Gärten” (With United Gardens), cultivation is trialled on the plots of the project participants, testing lettuce lines from Sativa breeding for mildew tolerance and other criteria such as taste and bolt resistance.

Lettuce seeds should only be lightly covered with soil and germinate in a cool place at 7-18°C. Temperatures above 20°C can slow down germination. Pre-cultivation of seedlings is recommended. When sowing early, protect from frost with a fleece cover. Do not plant too deep, otherwise there is a risk of rot. The optimal planting density for most lettuces is 10 plants per m². Staggered cultivation, sowing every 10-14 days, is important for continuous harvests. In order to limit cultivation risks and to be able to harvest all year round, it is advisable to grow several varieties per batch. Water regularly as soon as heads form or leaf growth increases significantly. Direct sowing can be useful for summer batches when watering is more difficult. Lactuca lettuces can be very susceptible to mildew. Infected plants should be harvested at the first sign of disease (brownish spots on the underside of the leaves), the infected leaves removed and the healthy leaves eaten quickly. Regular removal of weeds between lettuces improves the airflow and has a preventive effect against mildew, especially in summer and autumn.