When will the lettuce be planted? Introduction to planting time and sowing method of lettuce

Lettuce is an annual or biennial herbaceous crop of the genus Asteraceae lettuce. It is native to the Euro-Mediterranean coast and domesticated from wild species. The ancient Greeks and Romans first ate it, and it has a long history of being introduced into China. There are more cultivation in the southeast coast, especially in the suburbs of big cities and in Guangdong and Guangzhou. Let's take a look at when lettuce is planted.

Growth habits of lettuce

Lettuce likes cold environment and is neither cold-resistant nor heat-resistant. The suitable temperature for growth is 15-20 ℃, and the growth period is 90-100 days. The seeds were tolerant to low temperature and could germinate at 4 ℃. The optimum temperature for germination was 18-22 ℃, and almost no germination was found when the temperature was higher than 30 ℃. During the growth period, I like the cool climate, and 15-20 ℃ is the most suitable for growth, with high yield and good quality. The growth is poor when the temperature is higher than 25 ℃, but the cold tolerance is also strong. 0 ℃ or even short-term sub-zero low temperature does not hinder the growth. The root system is developed, the leaves are waxy, and the drought tolerance is quite strong, but cultivated on fertile and humid soil, the yield is high, the quality is good, and the soil pH value is 5.8-6.6.

Sowing time of lettuce

Lettuce likes the cold climate, so the sowing time is usually in spring and autumn. Spring usually begins to sow from February to April, and can be harvested from May to June, while autumn sowing can start at the end of August and can be harvested from September to October. Because the characteristics of different varieties of lettuce are different, when choosing the sowing time, you should first know the description of the seeds of lettuce you buy. Then sow seeds in combination with the above sowing time. Spring and summer are suitable for sowing loose leaf lettuce (such as cream lettuce, colored leaf lettuce), more heat-resistant, autumn and winter are suitable for sowing heading lettuce (also known as western lettuce), not heat-resistant.

Sowing method of lettuce

1. Sowing: lettuce seeds are too small and light, need to be accompanied by fine sand, mix evenly in a container, and then sprinkle on the soil, covering 0.5 cm, a thin layer, 15-20 degrees, about 3-5 days, it is difficult to germinate when the temperature is higher than 25 degrees. When planting in summer, soak the seeds for 1 night, then wrap them in wet gauze, put them in the freezer (about 5 degrees), and sow more than half of the seeds when they are white.

2, seedling stage: lettuce seedling stage to keep the soil moist, can not dry, keep the soil permeable, 2-3 true leaves time seedlings, plant spacing 5-8 cm.

3. Transplanting: when the lettuce seedlings grow to 5 or 6 true leaves, the seedlings should be watered thoroughly before moving, and the soil on the roots should be moved to a large basin. The distance of loose leaf lettuce plant is 15 cm, and the result is 30 cm. Water thoroughly, put the seedlings in a cool place in summer, stand firm in a week or so, and shine in the normal sun.

4. Fertilization: lettuce seedlings were fertilized once a week after transplanting (nitrogen fertilizer was the best mature organic fertilizer), organic fertilizer or total nitrogen, phosphorus and potassium compound fertilizer was applied again 2 weeks and 4 weeks after transplanting, and fertilization was stopped 2 weeks before harvest.

5. Watering: lettuce is watered early or late at high temperature, a small amount of water is better, but avoid waterlogging, the early growth stage is suitable for water control and keep moist.

When will the lettuce be sown? Planting time and method of lettuce

Lettuce planting time

Under normal conditions, lettuce can be cultivated in North China and the Yangtze River Basin in spring and autumn, and sown in South China from September to February of the following year.

Little knowledge of lettuce planting

Heading lettuce likes cold climate, and the suitable temperature for growth is 15 ℃ 20 min, which is the most suitable for the environment with large temperature difference between day and night and low temperature at night. The optimum temperature for heading is 10 ℃ 16 ℃, and the temperature is more than 25 mol. The high temperature inside the bulb will cause heart leaf necrosis and decay and poor growth. The seed germination temperature was 15 ℃ 20 ℃, which was higher than 25 ℃. The seed coat was blocked by water absorption and germinated poorly. Lettuce should be treated at low temperature when sowing in summer, sprouting in the freezer after soaking seeds, sowing seeds after bud dew, and dressing seeds with new high-fat film before sowing. Loose leaf lettuce is more heat-resistant, but it also grows poorly in high temperature season. Lettuce prefer slightly sour soil (pH6-6.3 is the best), and sandy loam or clay loam with strong water retention and good drainage is the best. Lettuce needs more nitrogen fertilizer, so base fertilizer should be applied more organic fertilizer before planting, and organic fertilizer should not be applied in the process of growth. There is no shortage of water during the growth period, especially during the heading period of lettuce, sufficient water is needed, such as dry and early lack of water, not only the leaf ball is small, but also the leaf taste is bitter and the quality is poor. But water can not be too much, otherwise the leaf ball will split, affect the appearance quality, but also easily lead to soft rot and Sclerotinia disease. Only with proper water and fertilizer management and timely spraying of Zhuangtuanling in the growth stage can lettuce with high yield and high quality be obtained.

When will the lettuce be planted? Planting time and method of lettuce

Lettuce, also known as leaf lettuce, lettuce, goose lettuce, etc., is an annual or biennial herb of the genus Asteraceae lettuce. Lettuce is one of the favorite vegetables with crisp and sweet texture and unique flavor. It also has the functions of heat-clearing and refreshing, analgesia and hypnosis, and has high planting value. So, when will the lettuce be planted? How should I plant it? The planting time and method of lettuce are introduced as follows.

Picture: lettuce planting

The planting time of lettuce

Lettuce likes the cold climate, so the sowing time is usually in spring and autumn. Spring usually begins to sow from February to April, and can be harvested from May to June, while autumn sowing can start at the end of August and can be harvested from September to October. Because the characteristics of different varieties of lettuce are different, when choosing the sowing time, you should first know the description of the seeds of lettuce you buy. Then sow seeds in combination with the above sowing time. Spring and summer are suitable for sowing loose leaf lettuce (such as cream lettuce, colored leaf lettuce), more heat-resistant, autumn and winter are suitable for sowing heading lettuce (also known as western lettuce), not heat-resistant.

Picture: lettuce planting

Second, the planting method of lettuce

1. Select and sow improved varieties: choose suitable varieties according to needs, such as glass lettuce, emperor, Caesar, heading lettuce, mosaic lettuce, Dahu 659 and so on.

two。 Prepare the seedbed: lettuce seedlings should choose water conservation, good fertilizer conservation, fertile sandy loam. Bed and soil preparation: 10 square meters of seedling bed with rotten organic fertilizer 10 kg, ammonium sulfate 0.3 kg, calcium superphosphate 0.5 kg, potassium sulfate 0.2 kg, fully mixed evenly to lay Harrow fine, pour enough bottom water, sow seeds after water infiltration.

3. Sowing and raising seedlings: in order to sow evenly, the seeds can be mixed with a small amount of fine sandy soil, covered with 0.3 cm thick tidal soil and covered with plastic film to keep moisturizing. The sowing rate is 30,50g per mu. When the seedlings begin to be unearthed, the plastic film on the border should be opened in time to prevent overgrowth. The suitable temperature of seedling bed should be controlled at 18 ℃ ~ 20 ℃ in daytime and 12 ℃ ~ 14 ℃ at night. Pay attention to ventilation and shade in case of strong light exposure. When the seedlings grow to 2-3 true leaves, the seedlings are divided according to the row spacing of 6-8 cm, and when they grow to 4-5 true leaves, they can be planted, and there is generally no shortage of water at the seedling stage.

Picture: lettuce planting

4. Scientific fertilization: lettuce requires clayey loam rich in organic matter and strong water and fertility conservation, lettuce likes slightly acidic, and the soil pH value is 5-7. For every 1000 kg of lettuce, it is necessary to absorb 2.5kg of nitrogen, 1.2kg of phosphorus and 4.5kg of potassium, among which heading lettuce needs more potassium. Nitrogen, phosphorus and potassium fertilizers should be used together during the growing period. The land where lettuce is planted should be ploughed deeply and carefully. Before planting, sufficient basic fertilizer should be applied, and 3000-3500 kg per mu of rotten farm manure should be applied. Turn deeply after application, pour enough bottom water, and make the border after seeing it dry.

5. Careful planting: the nursery bed will be irrigated one day before planting to make the seedling moist, and the next day the seedlings will bring as much soil as possible to reduce root damage. When planting, first open the ditch on the border surface, the ditch depth is 4cm 6 cm, plant 3 rows on the border surface 70 cm, apply the ternary compound fertilizer according to 25 kg per mu, then irrigate, put the seedlings to cultivate the soil and seal the ditch according to the plant distance of 24 cm, rake the border surface, cover the plastic film, and introduce the seedling out of the film.

6. Post-planting management: lettuce likes to be wet, and adequate water supply is required during the whole growth period. Slow seedling water was irrigated once after planting for 5-7 days. After watering the seedlings, the plots without plastic film were ploughed and loosened for two times to weed. After watering 3-4 times, combined with watering, nitrogen and phosphorus fertilizer was applied by stages, 15-20 kg per mu. Stop watering before harvest to facilitate storage and transportation.

Picture: lettuce planting

7. Pest control: the main diseases of lettuce are downy mildew, soft rot, virus disease and Sclerotinia sclerotiorum, among which Sclerotinia sclerotiorum and Sclerotinia sclerotiorum are more harmful, so rotation can be adopted, planting density should be reduced appropriately, watering should not be excessive, shallow hoe should be often done, soil surface should be kept dry, diseased plants should be pulled out in time, withered leaves can be removed and burned, agricultural streptomycin and ammonium benzoate can be sprayed after the disease occurs. Spray chlorothalonil every 5 to 7 days in high temperature and humidity season for preventive purposes. Insect pests are mainly aphids, thrips, ground tigers, etc., with omethoate, quick kill and other control.

8. Scientific harvest: non-heading lettuce can be harvested timely according to the market price, heading lettuce should be harvested after the leaf ball is tight, and the yield will be affected too early. If it is too late, the stem inside the leaf ball will elongate and the quality of leaf ball will decline.

[conclusion] lettuce likes a cold environment and is not resistant to cold or heat, so special attention should be paid to it in the process of planting. The time and method of growing lettuce are introduced in the above. Have you learned it?