When is the best time to sow lettuce?

There are many varieties of lettuce , including head lettuce , curly lettuce, etc. Different varieties differ in leaf shape, color and texture. Lettuce prefers a cool environment and is neither cold-resistant nor heat-resistant. The optimal growth temperature is 15℃-20℃. So when is the best time to sow lettuce?

When is the best time to sow lettuce?

Lettuce is a cool and moisture-loving vegetable, and its best sowing time varies by region and season.

The best time to sow spring lettuce is from mid-March to late April. The best time for summer planting is from late May to mid-June. The temperature is relatively cool and the sunshine is sufficient, which is suitable for lettuce growth. The best time for fall planting is mid-August to late September. The best time to plant winter lettuce is from late November to early February of the following year.

Lettuce Planting Method

1. Variety selection

When choosing lettuce varieties, priority should be given to those that are early maturing, high yielding, disease resistant and have good commercial properties. Recommended varieties include glass lettuce, cabbage lettuce, mosaic lettuce, Japanese big-leaf lettuce and red fresh lettuce. The soil for growing lettuce should be fertile, rich in organic matter, have good water and fertilizer retention capacity and air permeability, and be easy to irrigate and drain. Slightly acidic soil is preferred.

2. Seedling cultivation

The seedling period of lettuce is relatively short, and it is suitable to be grown in plastic greenhouses in early spring and autumn, and in solar greenhouses in winter. In summer, it can be cultivated under shade or in the open field. Seedlings can be raised by direct seeding or transplanting. The sowing rate is about 25-30 grams per 667 square meters, requiring a seedbed area of ​​15-20 square meters.

Seed treatment: Before sowing, mix the seeds with 50% carbendazim wettable powder, or soak them in warm water for 6 hours for germination, and keep them at a temperature of 15℃ to 18℃ until 80% of the seeds show white buds.

Sowing method: The soil for the seedbed should be sandy loam, add decomposed organic fertilizer and phosphorus and potassium fertilizer, mix well and then sow, and cover with plastic film and a small arch shed to keep moisture.

Seedbed management: Keep the germination temperature between 15℃ and 20℃, remove the plastic film promptly after emergence, control the temperature of the seedbed, and pay attention to ventilation and shading. When the seedlings have 2-3 true leaves, they should be transplanted. When they have 4-5 true leaves, they should be hardened for 3-5 days before being transplanted.

3. Planting

Before planting, the soil should be deeply plowed and sufficient base fertilizer should be applied. 3000-3500 kg of decomposed farmyard manure and 20 kg of nitrogen-phosphorus compound fertilizer should be applied per 667 square meters. The ridges are 10-15 cm high, 100-120 cm wide, and 30 cm apart. Water the seedbed to moisten it the day before transplanting, and pay attention to protecting the root system when digging up the seedlings. When planting, dig a trench 4-6 cm deep, place the seedlings at a spacing of 20-25 cm and cover with soil.

4. Harvest

When the lettuce plants are fully grown, harvest them in time according to demand and market conditions. Cabbage lettuce is best harvested when the leaf head is firm to ensure yield and quality. When harvesting, dead and old leaves should be removed, and the fruits should be graded and packaged.

In summary, the growth cycle of lettuce is relatively short, generally taking 60 to 90 days from sowing to harvesting, and the specific time depends on the variety and season planted. The best temperature for lettuce seeds to germinate is 18 to 22 degrees Celsius. It is resistant to low temperatures but afraid of high temperatures. Therefore, spring and autumn are ideal seasons for open-field cultivation. When sowing in summer, if the temperature is higher than 30 degrees Celsius, the seeds may need to be refrigerated for germination to ensure the germination rate.