Key Points of Lettuce Cultivation Techniques: A Complete Guide from Sowing to Harvest

Lettuce is a common vegetable grown for both its stem and leaves. The celtuce we usually eat is a stem-type lettuce, while romaine and other leaf lettuces are representatives of leaf-type lettuce. Lettuce prefers a cool climate; it is fairly cold-tolerant but not tolerant of high temperatures, making it suitable for cultivation in spring and autumn. Mastering the correct cultivation techniques is very helpful for improving the quality and yield of lettuce.

When growing lettuce, you generally first select a good plot, ideally with loose, fertile, well-drained soil, and avoid the previous crop being another Asteraceae plant of the same family. Before sowing, the seeds can be soaked in low-temperature water to promote germination, which makes the seedlings emerge more uniformly. During the seedling-raising period, pay attention to keeping warm and moist; once the seedlings have grown a few true leaves, they can be transplanted and set out, and a reasonable spacing between plants and rows should be maintained at planting.

After planting, water thoroughly to help the seedlings recover, then water frequently in small amounts according to soil moisture, avoiding waterlogging in the field, which can cause disease. Topdressing should be mainly nitrogen fertilizer, combined with phosphorus and potassium fertilizer. For stem-type lettuce, ensure sufficient nutrients during the stem-swelling stage, while for leaf-type lettuce, the focus is on promoting leaf growth. During the growing period, timely hoeing and weeding should also be carried out to keep the soil aerated.

Common problems with lettuce include premature bolting, downy mildew, and soft rot. Bolting is mostly caused by excessively high temperatures or improper water and fertilizer management and can be reduced by sowing at the right time and reasonably controlling temperature. Disease control should focus on prevention, paying attention to ventilation and reducing humidity, promptly removing diseased plants, and then applying targeted treatments in the early stages of the disease.

Stem-type lettuce can be harvested when the stem has fully swollen and the top leaves are flat and spread out; leaf-type lettuce can be harvested in batches by thinning or as whole plants, depending on need. Harvesting too late can easily lead to fiber development or bolting, affecting the taste, so the right timing must be grasped.