How to Grow Overwintering Lettuce? A Full Breakdown of the Latest Planting Techniques
Lettuce has strong adaptability and can be grown in spring and autumn or as an overwintering crop, and right now is the time to cultivate overwintering lettuce. As lettuce plants grow larger, their cold resistance declines, so overwintering lettuce generally needs to be grown in greenhouses, though it can also be grown in open fields in regions with warm winters. It is usually sown from mid to late September to early October and goes to market around the Spring Festival. Now let's take a look at the planting techniques for overwintering lettuce together with the editor.
1. Sowing and Seedling Raising
Lettuce seeds are small and are best raised as seedlings and then transplanted. Choose a seedbed with loam soil that has strong fertilizer and water retention capacity and is loose and fertile, and use the broadcast sowing method, sowing 100-150 grams per mu. After sowing, cover with a layer of fine soil, then cover with rice straw to retain moisture. You can also use shade netting laid on the ground to lower temperature and retain moisture. Remove the covering promptly after seedlings emerge. Once the seedlings are uniform, thin them to maintain a spacing of 3-4 cm, and apply one topdressing of 0.3% urea solution to promote seedling growth.
2. Transplanting
Before transplanting, plow the land 5-7 days in advance, and while plowing, apply 5000 kg of high-quality organic fertilizer, 50 kg of diammonium phosphate and 15 kg of potassium sulfate per mu as base fertilizer. The seedling age for overwintering lettuce should be kept at 30-40 days, with 4-5 leaves or more. Transplant from late October to November, keeping a plant and row spacing of about 33-40 cm. The day before transplanting, keep the seedbed soil moist and cover with plastic film. Take seedlings with plenty of soil attached and minimize root damage. Transplanting should be done on a sunny day, and the planting depth should fully bury the root system in the soil, but not so deep as to press on the heart leaves. Firm the soil slightly around the roots so they make full contact with the soil.
3. Field Management
After transplanting, repair the greenhouse film promptly. Ventilate promptly on sunny days, and close the greenhouse promptly to retain moisture during cold waves and frost. After the seedlings establish themselves, generally water with diluted manure water 2-3 times, and control the temperature to prevent the seedlings from growing leggy. Half a month after transplanting, to prevent leggy growth, spray once with a low concentration of paclobutrazol or chlormequat. If the tender stems still grow too fast and you want to delay the harvest according to market conditions, you can also spray chlormequat once every half month to promote the growth of the fleshy stems. Throughout the growing period, keep the soil moist, and control watering before harvest. One month after transplanting, apply heavy fertilizer, with 10-15 kg of urea, 10 kg of potassium fertilizer or 50 kg of plant ash per mu.
4. Harvest
Overwintering lettuce is generally sold around the Spring Festival. It can be harvested when the top leaves are level with the outer leaves. At harvest, cut along the surface of the bed, then strip off the lower leaves to expose the stem, while keeping the upper leaves to maintain freshness for sale. If you want to delay the harvest, you can pinch off the tips and remove the buds to control the tender stems and prevent them from growing too tall.
The above is an introduction to overwintering lettuce planting techniques. We hope it helps you. To learn more related knowledge, please stay tuned to us.