Lettuce planting technology and planting time

The roots of lettuce are relatively slender and densely distributed, mainly concentrated in the 20 to 30 cm soil layer. They have strong regeneration capabilities and are therefore very suitable for seedling raising and transplanting. During the seedling stage of lettuce, the stems are shortened. After the rosette leaves are formed, the stem gradually elongates and becomes enlarged, and the tissue becomes tender. Let’s learn about lettuce planting techniques and planting time.

1. Sowing time

Spring lettuce is usually sown in September and October, a little earlier in cool areas and a little later in warm areas. After overwintering, it will be on the market from March to May of the following year, with a growing period of 160-180 days. Sowing too early may cause the fleshy stems to freeze, and sowing too late may affect normal growth. Autumn lettuce is mostly sown in July and August, and is available in October and November. The growing period is 80-90 days. Summer lettuce is usually sown in early to mid-April.

2. Seed treatment

Summer lettuce and off-season lettuce need to be germinated at low temperatures before sowing. After soaking the seeds for 6-7 hours, wrap them with wet cloth and germinate them at 20-25℃ until 80% of the seeds turn white. Or soak the seeds for 1-2 hours, wrap them with wet cloth, place them in the well 30 cm from the water surface, water them 1-2 times a day, and they will germinate in 3-4 days. You can also soak the seeds for 24 hours, wrap them in a wet cloth, put them in the refrigerator or freezer, freeze them at -3-5℃ for 24 hours, then put them in a cool place, and they will germinate in 2-3 days.

3. Seedbed preparation

Choose a place with convenient water source, good drainage and shade to build the seedbed. The bed soil should be rich in organic matter, water-retaining and fertilizer-retaining, loose, and fertile with high nitrogen content.

4. Sowing method

When sowing spring lettuce seedlings in a greenhouse , first remove the film on the seedling bed, water the bottom sufficiently, and after the water seeps down, mix the seeds with a small amount of fine sand or fine soil, mix well, and then sow. Sow 25-30 grams of seeds per 10 square meters of seedbed. After sowing, cover with 0.30-0.50 cm of soil, cover tightly with film, and cover with shade net or straw thatch at night to keep warm. For open-field seedling cultivation, a small arch shed is added. Choose a cloudy day to sow summer lettuce. Sow the seeds in wet condition in early to mid-May and cover with film, then remove after the seedlings emerge. From late May to early to mid-July, use a small shed or flat shed to cover the plants with a shade net until seedlings emerge or two true leaves appear.

5. Seedling management

Keep the soil moist during the seedling stage and water it in the mornings and evenings on sunny days. When waiting for the seedlings to grow 2-3 true leaves, pay attention to thinning the seedlings, weeding, and gradually removing the covering. The seedling period is generally about 60 days. When the seedlings are 10 cm tall and have 4-5 true leaves, they can be transplanted.

6. Planting

For growing spring lettuce, choose fertile land, apply enough base fertilizer, and make beds 2-3 meters wide. The row spacing for planting is 30-32 cm. Before sowing autumn lettuce, water the bed thoroughly. After sowing, cover it with a layer of 30% to 40% concentration of decomposed pig manure and a layer of thin straw, or cover it with a black shade net, and sow sprouted seeds or wet seeds. Before germination, a double layer of floating surface is covered on the seedbed soil, and after germination, a silver-gray shade net is covered.

7. Field management

Spring lettuce has a long growing period and does not require top dressing in the first year. After the spring comes, inter-row cultivation, weeding and topdressing of fertilizers should be carried out. Fertilizer is mainly composed of decomposed human and livestock manure, which can also be combined with a small amount of urea, once every 10-15 days, for a total of 3-4 times. In order to promote the expansion of spring lettuce stems and put them on the market earlier, you can spray the leaves with 20-40PPM of 920 15-20 days before harvest, once every 5-7 days, for two consecutive times.

8. Harvest

In the later stage of spring lettuce's growth, when the inner leaves are flush with the outer leaves, it is mature and should be harvested in time. When harvesting, cut the plant down at ground level, trim off the roots, remove the old leaves, and only leave the top 3-4 tender leaves, then it can be put on the market.

The above is an introduction to the planting techniques and time of lettuce. As a common vegetable , lettuce has a stable market demand and can be cultivated in the open field or in a greenhouse.