When to plant lettuce? It can be planted all year round
AbstractLettuce can be planted in spring, summer and autumn, and can also be planted in winter in greenhouses. Spring sowing is generally carried out from February to April, autumn sowing from July to August, and summer sowing needs to avoid the intense heat. The planting time of lettuce varies with different regions and different varieties. Loose-leaf lettuce is suitable for spring sowing, heading lettuce is suitable for winter sowing. In high-cold regions, winter sowing is generally used; in North China, both spring and autumn sowing are possible; in South China, cold-frame seedling raising should be carried out from late January to early February.
I. Lettuce planting time
1. By season: According to the different climates of each region and the different lettuce varieties, the sowing time of lettuce varies. The most common lettuce planting time is divided into two crops, spring and autumn, sown respectively from February to April and from July to August. If greenhouse planting technology is used, sowing is also possible in winter; it is enough to master the temperature for sowing and sprouting lettuce.
Lettuce leaves are delicate; the temperature for sowing and sprouting is between 5-10 degrees, while the growing temperature should be controlled at 15-20 degrees, because it prefers cool conditions, so planting should avoid the intense heat, and lettuce should not be planted in severe cold either.
2. By region: In high-cold regions such as Northeast and Northwest China, spring sowing is generally used; in the Yangtze River Basin and North China, both spring and autumn sowing are possible; in South China, autumn sowing is used; in the Shanghai area, if spring sowing is used, the time should generally be correspondingly earlier, with cold-frame seedling raising in late January and early February.
3. By variety: Loose-leaf lettuces such as butterhead lettuce are relatively heat-tolerant and can be sown in spring and summer; heading lettuces such as iceberg lettuce are not heat-tolerant and are suitable for sowing in autumn and winter.
II. Planting precautions
1. Sowing stage
(1) Making beds: When sowing, beds should be made; the beds should be 1.2-1.3 m wide and 10 cm-12 cm high, and drainage ditches should be built to prevent rainwater accumulation.
(2) Seedling transplanting: Because lettuce seeds are relatively expensive, the method of seedling transplanting is mostly used for cultivation. Generally, when transplanting seedlings, attention should be paid to sowing appropriately sparsely, with the aim of cultivating strong seedlings. When the seedlings grow to 5-8 cm, pits can be dug in the beds for planting. Note that the spacing is generally about 10-12 cm, and the row spacing is about 20 cm.
(3) Direct sowing: The density of direct sowing is generally controlled at 2-3 seeds per cm, and covered with 0.3-0.5 cm of fine soil. For autumn direct sowing, the seeds need to be soaked for 12 hours, wrapped in wet gauze, and placed in a 5-6 degrees Celsius environment for low-temperature treatment for 2 days, then taken out when most of the seeds have sprouted. Summer and autumn are high-temperature and rainy seasons; if sowing at this time, attention should be paid to using a shade net.
2. Environment and varieties
(1) Environment: 15-20 degrees Celsius is the temperature required for lettuce growth, and a soil pH value of 5.5-6.8 is most suitable.
(2) Varieties: Varieties such as Salinas and Beishan No. 3 are all relatively good.
3. Field management
(1) After applying fertilizer, the soil should be deeply plowed and leveled.
(2) About 5 days after sowing, nitrogen watering and fertilizing can be carried out. When the leaf crown grows best, phosphate fertilizer can be applied to the leaves, and fertilization should be stopped two weeks before harvest.
(3) Water control should be moderate; in high-temperature weather, watering should be done every day, and in the rainy season, drainage should be carried out.
(4) After lettuce matures, it should be harvested in time.