Summer sowing needs to avoid extremely hot weather, and different regions and varieties of lettuce have different planting time. Lettuce is native to Europe and the Mediterranean. It used to be planted in the south, but the planting scope is expanding, and now it is planted in the north and south. Prepare soil, foam boxes and vegetable pots, and put fertile and loose soil with good drainage. Humus soil can be used, and the remaining skins of vegetables and fruits can also be added to the soil. After planting, water it once, then attach a layer of fine soil and maintain it in a semi-cool environment.
After sowing, water should be poured every 2-3 days to keep the soil moist, and it takes about 15 days to germinate. Then, judge whether to water according to the dryness of the soil. If the sowing is dense, it can be transplanted after rainy or cloudy days, and no fertilizer is applied during the growing period.
Key points of lettuce planting management
1, scientific watering
Lettuce can be watered once after planting. After the slow seedling stage, water should be given according to the dry humidity of the soil, usually once every seven days. If the temperature is low, the watering frequency should be reduced. If the temperature is high and the air is dry, you can water it once a day or spray water to moisturize it, but you can't water it too much and there can be no water accumulation.
2, intertillage weeding
After the slow seedling stage, lettuce needs to be loosened in time to enhance air permeability and drainage, to prevent soil hardening and affect root respiration and growth. Pay attention to the depth of intertillage so as not to hurt the roots. Lettuce mainly eats stems and leaves, and it is best not to use herbicides. Manual weeding is recommended.
3. Rational topdressing
Before planting lettuce, sufficient base fertilizer should be applied. The fertilizer can be decomposed farmyard manure, and there is no need for topdressing in the early growth stage. In the prosperous period, nitrogen fertilizer can be applied when watering to promote leaf growth, and topdressing can be done once every 15 days. At this time, NPK compound fertilizer is better.
4, pest control
Soft rot, virus disease, dry rot, etc. Will happen during the growth of lettuce. The main pests are liriomyza sativae, aphids, thrips and so on. It is necessary to weed in time, increase the application of phosphorus and potassium fertilizer to increase disease resistance, and also need to spray chemicals in time for control. Stop taking medicine ten days before harvest.