How to grow lettuce from seed? Sowing methods and key planting management points

Lettuce originated along the Mediterranean coast of Europe, domesticated from wild species. It has a long history of introduction into China, and is widely cultivated along the southeast coast, especially in the suburbs of major cities and in the Guangdong and Guangxi regions. It has extremely high cultivation value. Common cultivars include glass lettuce, Emperor, Caesar, head lettuce, curly-leaf lettuce, and Dahou 659. Now let us take a look at how to grow lettuce from seed!

Growth habits of lettuce

Lettuce prefers a cool environment; it is neither cold-tolerant nor heat-tolerant. The suitable growing temperature is 15-20°C, and the growth period is 90-100 days. The seeds are relatively tolerant of low temperatures and can germinate at 4°C. The optimum germination temperature is 18-22°C, and they barely germinate above 30°C. During the growing period it prefers a cool climate, growing best at 15-20°C with high yield and excellent quality. Growth is poorer when temperatures stay above 25°C, but it is also quite cold-tolerant, and 0°C or even short periods of subzero low temperatures do not greatly hinder growth. The root system is well developed, the leaf surface is waxy, and drought tolerance is quite strong. However, when cultivated in fertile, moist soil, the yield is high and the quality is good. The suitable soil pH is 5.8-6.6.

How to grow lettuce from seed?

1. Sowing time: Generally, the sowing period for lettuce is from August to February of the following year. The optimal sowing time is from mid-October to mid-December. Sowing is also possible in early March and early July, though the growth period is shorter and the yield lower. In winter and early spring, cultivate in large or small plastic tunnels; in summer, cultivate under shade netting or in shaded shelters. For the seedling bed, apply 1500 kg of decomposed farmyard manure and 20 kg of superphosphate per 60 sq m, then plow and mix evenly and level. For raising seedlings and transplanting, each mu of cultivated field requires 20-30 sq m of seedling bed and 25-30 g of seed.

2. Seed germination: When sowing lettuce in the high-temperature season, the seeds must be subjected to low-temperature germination. First soak them in well water for about 6 hours, rub and wash them, take them out, wrap them in moist gauze, and place them at 15-18°C to germinate, or hang them in a water well to germinate, or place them in a refrigerator (with the temperature controlled at about 5°C), and after 24 hours place the seeds in a cool place to germinate at a maintained temperature. Alternatively, soak the seeds in a 0.2 per thousand "920" solution for 24 hours, which can smoothly break the dormancy of lettuce seeds, and complete germination can be achieved in 2-3 days. When 80% of the seeds have sprouted white, they should be sown in time.

3. Raising seedlings and transplanting: Before sowing, water the seedling bed thoroughly. Mix the seeds evenly with an equal amount of moist fine sand and broadcast them, then cover with about 0.5 cm of soil. When 2-3 true leaves appear, thin and divide the seedlings in time. For seedling raising in large tunnels or open fields in winter and spring, pay attention to keeping the seedling bed warm, and at the same time control the amount of watering to prevent excessive humidity. For open-field seedling raising in summer, pay attention to covering with shade netting and water 2-3 times a day to keep the soil moist.

Lettuce planting management

1. Scientific fertilization: Lettuce requires clay loam rich in organic matter with strong water and fertilizer retention. Lettuce prefers slightly acidic soil, with a suitable soil pH of 5-7. For every 1000 kg of lettuce produced, it needs to absorb 2.5 kg of nitrogen, 1.2 kg of phosphorus, and 4.5 kg of potassium, among which head lettuce requires more potassium. During the growing period, nitrogen, phosphorus, and potassium fertilizers need to be used in combination. The plot for planting lettuce should be deeply plowed and finely prepared. Before planting, apply sufficient base fertilizer, with 3000-3500 kg of decomposed farmyard manure per mu. After application, plow deeply, water the bottom thoroughly, and make beds after the soil dries.

2. Careful planting: The day before planting, irrigate the seedling bed to moisten the seedling clumps. The next day, lift the seedlings with as much soil as possible to reduce root damage. When planting, first open furrows on the bed surface, with a furrow depth of 4-6 cm. On a 70 cm bed surface, plant 3 rows. After opening the furrows, apply 25 kg per mu of compound fertilizer and then irrigate. After the water seeps in, place the seedlings at a spacing of 24 cm, cover with soil, and close the furrows. Rake the bed surface level, cover with plastic film, and guide the seedlings out through the film.

3. Post-planting management: Lettuce prefers moisture and requires a sufficient water supply throughout the entire growth period. Water once 5-7 days after planting to help the seedlings recover. After watering for seedling recovery, carry out 2 rounds of intertillage, loosening the soil, and weeding on plots not covered with plastic film. After that, water 3-4 times, and in combination with watering, apply nitrogen and phosphorus fertilizers in stages, at 15-20 kg per mu. Stop watering before harvest to facilitate storage and transport.

4. Pest and disease control: The main diseases of lettuce include downy mildew, soft rot, viral disease, and sclerotinia, among which sclerotinia and soft rot are more harmful. Measures can include crop rotation, appropriately reducing planting density, not watering too much, frequently shallow hoeing, keeping the soil surface dry, promptly pulling out diseased plants, removing dead leaves and burning them in a centralized manner. After disease onset, spray agricultural streptomycin and amobam. In hot and humid seasons, spray chlorothalonil once every 5-7 days for prevention. The main pests include aphids, thrips, and cutworms, which can be controlled with omethoate, fenvalerate, and similar agents.

How to grow lettuce, lettuce planting methods, key points of lettuce cultivation

Lettuce is known as the "queen of vegetables," rich in various vitamins and trace elements; its stems and leaves contain lactucin, which can relieve pain, induce sleep, and lower cholesterol; it contains an interferon inducer, which can stimulate the human body to produce antiviral proteins and has the effect of inhibiting viruses.

Other names for lettuce: leaf lettuce, goose lettuce, wochai, mai chai. It belongs to the Asteraceae family, Lactuca genus. According to leaf growth form, lettuce can be divided into loose-leaf lettuce and head lettuce. When sowing in spring and summer, loose-leaf lettuce should be chosen. Head lettuce is also called western lettuce or American lettuce. It is less heat-tolerant than loose-leaf lettuce and has a shorter sowing period, making it more suitable for sowing in autumn and winter.

Suitable regions: It can be planted in all provinces and regions of China. Planting season: September-October (it can be sown year-round, but spring and autumn are best; in northern winters it needs to be maintained indoors).

Growth habits

Lettuce prefers a cool environment; it is neither cold-tolerant nor heat-tolerant. The suitable growing temperature is 15°C-20°C, and the growth period is 90-100 days. The seeds are relatively tolerant of low temperatures and can germinate at 4°C. The optimum germination temperature is 18-22°C, and they barely germinate above 30°C.

During the plant's growing period, it prefers a cool climate, growing best at 15-20°C with high yield and excellent quality; when continuously above 25°C, growth is poorer, the leaf texture is coarse and old, and there is a slight bitter taste. However, it is also quite cold-tolerant, and 0°C or even short periods of subzero low temperatures do not greatly hinder growth.

Lettuce has a well-developed root system and a waxy leaf surface, and its drought tolerance is quite strong. However, when cultivated in fertile, moist soil, the yield is high and the quality is good. The suitable soil pH is 5.8-6.6.

Raising seedlings

(1) Usually seedlings are raised and then transplanted. First water the potting soil thoroughly. Mix the seeds with fine sand and broadcast them on the soil surface, then cover with about 0.5 cm of soil. At 15-20°C, they germinate in about 3-5 days. When the temperature is above 25°C, the germination rate is relatively low, so when sowing at high temperatures, germination must be promoted: soak the seeds in water for about 6 hours, take them out, wrap them in cloth, and place them in a refrigerator crisper at about 5°C to germinate. Sow again when about 3/4 of the seeds have sprouted white.

(2) During the seedling stage, avoid drought, but do not water excessively. Thin once when 2-3 true leaves appear, with a plant spacing of about 5 cm.

(3) Transplant when 5-6 true leaves appear. For loose-leaf lettuce, the plant spacing is about 15 cm; for head lettuce, about 30 cm. Generally carry this out on a sunny afternoon. The roots must all be buried in the soil, and water thoroughly. After they survive, manage normally.

Daily management

(1) One week after planting, spray once with decomposed organic fertilizer mainly based on nitrogen fertilizer; 2 weeks and 1 month after planting, spray once more each time with decomposed organic fertilizer, requiring a complete fertilizer of nitrogen, phosphorus, and potassium. If the plants lack fertilizer, increase the number of fertilizations as needed, but stop fertilizing about 2 weeks before harvest.

(2) Appropriately control water in the early growth stage. During the period of vigorous leaf growth, the water demand for harvest retention is relatively large, and the soil should be kept moist, but waterlogging and water accumulating between leaves should be avoided. Generally water once every 2-3 days. At high temperatures, water in the morning and evening, and it is best to water lightly and frequently. Gradually reduce the amount of watering before harvest.

(3) It prefers cool conditions, with an optimum growth temperature of 15-20°C. Growth is poor at high temperatures, so in summer pay attention to shading and cooling.

Harvest

When the plant has grown sufficiently but has not yet aged, it can be harvested at the right time by pulling it directly from the soil. If the main stem rapidly elongates, the plant is often aged and not suitable for eating.

Key cultivation points

Choose and sow good seeds

Choose suitable varieties according to need, such as glass lettuce, Emperor, Caesar, head lettuce, curly-leaf lettuce, and Dahou 659.

Prepare the seedling bed

For raising lettuce seedlings, it is best to choose fertile sandy loam with good water and fertilizer retention. Seedling bed soil preparation: for a 10 sq m seedling bed, use 10 kg of decomposed organic fertilizer, 0.3 kg of ammonium sulfate, 0.5 kg of superphosphate, and 0.2 kg of potassium sulfate. Mix thoroughly, spread level, rake fine, water the bottom thoroughly, and sow after the water seeps in.

Sowing and raising seedlings

To make broadcasting even, a small amount of fine sandy soil can be mixed into the seeds when sowing. After sowing, cover with 0.3-0.5 cm of moist soil and cover with plastic film to retain moisture. The sowing rate is 30-50 g per mu. When the seedlings begin to emerge, promptly uncover the plastic film on the bed surface to prevent spindly growth. The seedling bed temperature should be controlled at 18°C-20°C during the day and 12°C-14°C at night. Pay attention to ventilation and air exchange, and provide shade if there is strong sunlight exposure. When the seedlings grow to 2-3 true leaves, divide them at a spacing of 6-8 cm between plants and rows. When they grow to 4-5 true leaves, they can be planted. During the seedling stage, generally do not water unless the soil is short of water. To prevent seedling-stage diseases, spray 1-2 times with a 600-fold dilution of 75% chlorothalonil solution.

Scientific fertilization

Lettuce requires clay loam rich in organic matter with strong water and fertilizer retention. Lettuce prefers slightly acidic soil, with a suitable soil pH of 5-7. For every 1000 kg of lettuce produced, it needs to absorb 2.5 kg of nitrogen, 1.2 kg of phosphorus, and 4.5 kg of potassium. Among these, head lettuce requires more potassium. During the growing period, nitrogen, phosphorus, and potassium fertilizers need to be used in combination. The plot for planting lettuce should be deeply plowed and finely prepared. Before planting, apply sufficient base fertilizer, with 3000-3500 kg of decomposed farmyard manure per mu. After application, plow deeply, water the bottom thoroughly, and make beds after the soil dries.

Alright, that is all from the editor here. The rest is up to everyone to slowly understand for yourselves. Good luck to everyone. Please follow Succulent Garden more, thank you!

Key points of winter lettuce planting techniques

As the weather warms, vegetable prices in many regions begin to rise, and the business of winter growers has also improved. Recently we learned from Tangshan City, Hebei Province, that because the weather turned colder and local production grew slowly, lettuce prices soared. So what are the key points of winter greenhouse production and planting?

Variety selection: Choose mid-to-late maturing head lettuce varieties with strong cold resistance for cultivation.

Cultivation date: For solar greenhouse cultivation, planting can be done from mid-to-late November to late January of the following year, and harvest from early-to-mid January to early March.

Raising seedlings: Choose fertile sandy loam, break it up finely, and make flat beds. Then apply 100 kg of sifted high-quality manure and 0.5 kg of potassium dihydrogen phosphate per 10 sq m, mix thoroughly, level the bed surface, water, and broadcast seeds after the water seeps down. Generally dry seeds are used for sowing, but seeds can also be soaked and germinated before sowing. When sowing dry seeds, first dress the seeds with 75% chlorothalonil wettable powder at 0.3% of the seed weight, but it should not be left for too long. For soaking and germinating, first soak in warm water at 20°C for 6-7 hours, take out, wrap in a cloth bag, and place at 20°C to germinate, rinsing once a day with clean water. Complete germination occurs after 2-3 days. Choose a windless, sunny morning for sowing, sowing 3-5 g of seed per sq m of seedling bed. After sowing, cover with a 3-5 mm layer of fine soil.

Land preparation and fertilization: Before planting, apply 5000 kg of decomposed organic fertilizer and 30-40 kg of compound fertilizer per mu. After deep plowing, make flat beds; if covering with plastic film, small raised beds can be made.

Planting: For solar greenhouse cultivation, the row spacing is generally 40 cm and the plant spacing 30 cm. Before lifting the seedlings, water and cut the clumps, keeping more soil. Plant by opening furrows or digging holes, then after closing the furrows and leveling the beds, water thoroughly for establishment.

Management after planting: After planting, maintain the daytime temperature at 20°C-24°C and the nighttime temperature above 10°C. During the seedling recovery period, carry out 1-2 rounds of intertillage and soil loosening. After seedling recovery, lower the temperature appropriately, with 15°C-20°C suitable during the day, and water for seedling recovery 7-10 days after recovery, while lightly applying chemical fertilizer at about 10 kg per mu. After that, intertill again and appropriately restrain growth. About 15 days later, when the rosette leaves have grown and the heart leaves begin to head, apply 15-20 kg of compound fertilizer or ammonium nitrate, and apply fertilizer once more during the heading stage. In winter, do not water too frequently, to prevent lowering the ground temperature or causing excessive humidity. When entering the heading stage, supply water evenly, and by all means avoid alternating drought and flooding, so as to prevent head cracking or the head leaves opening and growing. Stop watering 3-5 days before harvest.