Lettuce in all seasons of the year can be planted, spring lettuce can be in February-March seedlings, summer lettuce in April-May planting, fall lettuce in July-September sowing propagation, lettuce specific planting time is still to be decided according to local temperatures, the Yangtze River Basin is generally in the September-October sowing.

Lettuce is also known as lettuce, Asteraceae lettuce lettuce species can form a fleshy tender stem varieties, 2012 herbaceous plants. Alias stem lettuce, lettuce shoots, green shoots, lettuce. Production period: January-April. Lettuce originates from the Mediterranean coast and was introduced to China around the fifth century. Aboveground stems are edible, stem skin white-green, stem flesh crisp, young stems bright green, mature transformation white-green.

Mainly edible fleshy young stems, can be eaten raw, cold, fried, dried or pickled, young leaves can also be eaten. The stems and leaves contain lettuce pigments, and lettucein (C11H14O4 or C22H36O7) is contained within. Lettuce is sensitive to the acidity and alkalinity of the soil and is suitable for planting in slightly acidic soil. Lettuce has a shallow root system, weak absorption capacity, and high oxygen requirements. Sandy loam and loamy soil are preferred for planting lettuce.

Summer lettuce high-yield interpretation:

Lettuce is a cold shade crop, do not tolerate high temperature, summer planting need to choose heat-resistant, not easy to moss, disease-resistant, high-yield varieties, and soak seeds before planting to promote germination treatment, you can soak the seeds in cold water for 8-12 hours.

To be the seed water absorption rate of 70% to 80% when wrapped in wet gauze, maintain a low temperature of 4-5 ℃, treatment 24-28 hours, placed in 15-20 ℃ temperature conditions moisturizing germination, after 2-3 days most of the seeds can be sown when the whitening. After sowing, timely spraying of new high fat film can retain moisture, activate the surface layer of the slate density, improve the rate of seedling emergence.

Summer lettuce root shallow, weak absorption capacity, coupled with rapid plant growth in the summer, need more fertilizer, so field management should be heavy fertilizer and water, in order to facilitate plant growth and prosperity. After the seedlings live, the interval of 3-5 days combined with watering a diluted manure water, and even sprayed 3 times vegetable strong stem spirit, in order to improve the plant water absorption capacity, promote lettuce stem thick, leaf color tender, high yield and excellent yield.

The harvesting period of lettuce in summer is also the most rapid period of moss extraction, if you do not harvest in time will result in the quality of the plant moss extraction hardened, or even hollow situation, greatly affecting the yield and quality of lettuce; therefore, lettuce need to harvest in time to do harvesting, when the lettuce main stem tip and the highest leaf blade leaf tip flat for the harvesting of the right time, harvesting 10 days before the ban on the use of pesticides.

Reference: Baidu Encyclopedia - Lettuce