What is the time and method of growing lettuce? If you do well in these points, you can get a high yield!

Lettuce is a common vegetable, which contains lettuce in stems and leaves and has high nutritional value. It has strong adaptability and can be cultivated in spring and autumn or overwintering, mainly in spring and harvested in summer. So, what is the time and method of growing lettuce? If you do well in these points, you can get a high yield!

First, planting time

Spring lettuce: raising seedlings in greenhouse from December to March and in open field from mid-February to late March

Summer lettuce: cultivated in open field from April to mid-May, covered with sunshade net from late May to July, direct seeding or high-density planting

Autumn lettuce: sowing, seedling raising and transplanting with sunshade net from July to September

Overwintering lettuce: raising seedlings in the open field from October to November.

II. Planting methods

1. Variety selection

Overwintering lettuce and spring lettuce choose varieties with cold tolerance, strong adaptability and late bolting, such as cold-resistant white leaf tip, cold-resistant second white bark, bitter leaf and so on. Summer and autumn lettuce, choose heat-resistant early-maturing varieties, such as heat-resistant white leaf tip, bitter clover leaf, heat-resistant big mosaic leaf, special heat-resistant second white bark, rape and so on.

2. Soil preparation

Select land with high dryness and good drainage as seedbed and apply 4000-5000 kg of rotten organic fertilizer per mu or 500kg of compound fertilizer as base fertilizer 5-7 days before sowing. Turn deeply before and after soil preparation, flatten and fine, cover with plastic film and wait for sowing.

3. Raising seedlings

If the seeds are sown from May to September, it is difficult for the seeds to germinate because of the hot temperature, so they need to germinate at a low temperature before sowing. Soak the seeds in cold water for 6-7 hours, wrap them in a wet cloth and germinate at 20-25 ℃ until 80% of the seeds are white.

4. Sowing seeds

Sow wet seeds to cover the film, remove after emergence. After sowing, cover 1 layer of rotten pig manure residue of 3-4% concentration and cover 1 layer of thin straw, or cover black sunshade net, sow bud seeds or wet seeds. The double-layer floating surface is covered on the soil of the seedling bed before emergence, and the silver-gray sunshade net is covered after emergence. Watering fertilizer in the morning and evening, keeping the bed soil moist, weeding seedlings in time.

5. Colonization

When planting, choose the loam with good drainage conditions and apply 4000-5000 kg of rotten organic fertilizer per mu. It is deeply turned and flattened to make a high border 1.20-1.50 meters wide. Water the seedbed before raising the seedlings. The seedlings were 25-30 days old and were planted with 5-6 leaves. The row spacing was 20 cm × 27 cm, and the depth should be buried to the base of the first petiole.

6. Field management

Watering in time after transplanting, watering ammonium hydrogen with water and adding 10 kg calcium per mu after transplanting survived. In the future, water and fertilizer control, strengthen mid-tillage, rosette stage to leaf ridge watering and topdressing, urea 10kg / mu, potassium sulfate 5kg / mu, dry and wet later. When the stem began to enlarge, the third topdressing was applied with 50 kg of ternary compound fertilizer, 10 kg of potassium sulfate and 15 kg of urea per mu.

7. Harvest

Young plants can be harvested on the market at any time before the stem is fully enlarged, and the harvest period of lettuce is also the fastest period of bolting. If it is not harvested in time, the quality of the plant will become hard or even hollow after bolting, which will greatly affect the yield and quality of lettuce. Therefore, lettuce should be harvested in time. When the tip of the main stem of lettuce is at peace with the tip of the highest leaf, the use of pesticides is prohibited 10 days before harvest.