When to Plant Lettuce? A Detailed Guide to Planting Time and Sowing Methods
Lettuce is an annual or biennial herbaceous crop of the genus Lactuca in the Asteraceae family. It originated along the Mediterranean coast of Europe and was domesticated from wild species. The ancient Greeks and Romans were the first to eat it. It has a long history of introduction into China, and is widely cultivated along the southeast coast, especially in the suburbs of major cities, and in the Guangdong and Guangxi regions. Let's take a look below at when lettuce should be planted!
Lettuce's Growth Habits
Lettuce prefers a cool environment; it tolerates neither cold nor heat. The suitable growing temperature is 15-20°C, and the growth period is 90-100 days. The seeds are fairly tolerant of low temperatures and can germinate at 4°C. The optimal germination temperature is 18-22°C, and above 30°C they barely germinate. During growth it likes a cool climate, growing best at 15-20°C with high yields and excellent quality; growth is poorer when temperatures stay above 25°C, but its cold tolerance is also quite strong, and 0°C or even short periods of sub-zero temperatures do not greatly hinder growth. It has a well-developed root system and waxy leaves, with strong drought tolerance, but when grown in fertile, moist soil it yields more and has better quality. The suitable soil pH is 5.8-6.6.
Lettuce Sowing Time
Lettuce likes a cool climate, so sowing is generally done in spring and autumn. In spring, sowing usually begins in February to April, and harvest can be done in May to June. For autumn sowing, you can start sowing at the end of August, and harvest in September to October. Because different lettuce varieties have different characteristics, when choosing the sowing time you should first read the instructions for the lettuce seeds you bought, and then sow according to the sowing times above. Spring and summer are suitable for sowing loose-leaf lettuce (such as butterhead lettuce and colored-leaf lettuce), which is more heat-tolerant. Autumn and winter are suitable for sowing head lettuce (also called iceberg lettuce), which is not heat-tolerant.
Lettuce Sowing Methods
1. Sowing: Lettuce seeds are very small and light, so they need to be mixed with fine sand. Put them in a container and stir evenly, then scatter onto the soil and cover with 0.5-1 cm of soil, just a thin layer. At 15-20 degrees they germinate in about 3-5 days; when the temperature is above 25 degrees germination is difficult. When planting in summer, germination must be forced: soak the seeds for 1 night, then wrap them in damp gauze and place in the refrigerator's chilling compartment (around 5 degrees). Sow again when more than about half the seeds have sprouted.
2. Seedling stage: During the lettuce seedling stage, keep the soil moist, not dry, and keep the soil well-drained. Thin the seedlings when they have 2-3 true leaves, with a plant spacing of 5-8 cm.
3. Transplanting: When lettuce seedlings grow to 5-6 true leaves, transplant them. Before transplanting, water thoroughly, and move them together with the soil on the roots into a large pot. For loose-leaf lettuce, plant spacing is 15 cm, and 30 cm for head lettuce. Water thoroughly. In summer, first place them in a cool spot to recover; after about 1 week, once the roots have taken hold, give them normal sunlight.
4. Fertilizing: One week after transplanting lettuce seedlings, apply fertilizer once (nitrogen fertilizer is main; well-rotted organic fertilizer is best). Two weeks and again four weeks after transplanting, apply organic fertilizer or a compound fertilizer mainly of nitrogen, phosphorus, and potassium once each. Stop fertilizing 2 weeks before harvest.
5. Watering: When lettuce is grown in high temperatures, water in the early morning and evening. Small amounts and frequent watering are best, but avoid waterlogging. In the early growth stage it is suitable to control water, keeping it just moist.
When to Sow Lettuce? Lettuce Planting Time and Planting Methods
Lettuce Planting Time
Under normal conditions, lettuce is suitable for cultivation in both spring and autumn in North China and the Yangtze River basin, while in South China it can be sown from September to February of the following year.
Little-Known Facts About Growing Lettuce
Head lettuce likes a cool climate, with an optimal growth temperature of 15—20°C, and it does best in environments with a large day-night temperature difference and lower nighttime temperatures. The optimal temperature for head formation is 10—16°C. When the temperature exceeds 25°C, the inner leaves of the head can become necrotic and rot due to the high heat, and growth is poor. The seed germination temperature is 15—20°C; above 25°C, germination is poor because the seed coat's water absorption is blocked. When sowing lettuce in summer, low-temperature treatment is needed: after soaking the seeds, place them in the refrigerator's chilling compartment to force germination, and sow only after the sprouts have emerged. Before sowing, treat the seeds with New High Lipid Membrane. Loose-leaf lettuce is relatively heat-tolerant, but in hot seasons it also grows poorly. Lettuce likes slightly acidic soil (pH 6—6.3 is best), and sandy loam or clay loam with strong water retention and good drainage is best for cultivation. Lettuce needs more nitrogen fertilizer, so before planting, more organic fertilizer should be applied as base fertilizer; during growth, no more organic fertilizer is applied. During the growth period it must not lack water, especially during the head-forming stage of head lettuce, when sufficient moisture is needed. If it is dry and lacks water, not only will the head be small, but the leaves will taste bitter and the quality will be poor. However, there should not be too much water either, otherwise the head will split, affecting its appearance quality and easily leading to soft rot and sclerotinia rot. Only with proper water and fertilizer management, and timely spraying of Zhuangjingling during the growth stage, can high-yield, high-quality lettuce be obtained.
When Is the Best Time to Plant Lettuce? Lettuce Planting Time and Methods
Lettuce, also known as leaf lettuce, wochai, and goose lettuce, is an annual or biennial herbaceous plant of the genus Lactuca in the Asteraceae family. Lettuce is one of everyone's favorite vegetables, crisp and tender with a slight sweetness and a unique flavor. It also has effects such as clearing heat and refreshing the mind, and relieving pain and promoting sleep, giving it high cultivation value. So, when is the best time to plant lettuce? How should it be grown? The planting time and methods for lettuce are introduced below.
Image: Lettuce planting
I. Lettuce Planting Time
Lettuce likes a cool climate, so sowing is generally done in spring and autumn. In spring, sowing usually begins in February to April, and harvest can be done in May to June. For autumn sowing, you can start sowing at the end of August, and harvest in September to October. Because different lettuce varieties have different characteristics, when choosing the sowing time you should first read the instructions for the lettuce seeds you bought, and then sow according to the sowing times above. Spring and summer are suitable for sowing loose-leaf lettuce (such as butterhead lettuce and colored-leaf lettuce), which is more heat-tolerant. Autumn and winter are suitable for sowing head lettuce (also called iceberg lettuce), which is not heat-tolerant.
Image: Lettuce planting
II. Lettuce Planting Methods
1. Choose good seeds to sow:Choose suitable varieties according to your needs, such as Glass Lettuce, Emperor, Caesar, head lettuce, curly-leaf lettuce, Dahu 659, etc.
2. Prepare the seedbed:For lettuce seedling raising, choose fertile sandy loam with good water and fertilizer retention. Seedbed soil preparation: for 10 sq m of seedbed, use 10 kg of well-rotted organic fertilizer, 0.3 kg of ammonium sulfate, 0.5 kg of superphosphate, and 0.2 kg of potassium sulfate. Mix thoroughly, spread flat and rake fine, water thoroughly to the bottom, and sow after the water seeps in.
3. Sowing and seedling raising:To make broadcasting even, a small amount of fine sandy soil can be mixed into the seeds when sowing. After sowing, cover with 0.3-0.5 cm of moist soil and cover with plastic film to retain moisture. The sowing rate is 30-50 grams per mu. When the seedlings begin to emerge, promptly uncover the plastic film on the bed surface to prevent spindly growth. The seedbed temperature should be controlled at 18°C-20°C during the day and 12°C-14°C at night. Pay attention to ventilation; if there is strong direct sunlight, shade is needed. When the seedlings grow to 2-3 true leaves, thin and transplant them at a plant-row spacing of 6-8 cm. When they grow to 4-5 true leaves, they can be set out. During the seedling stage, generally do not water unless the soil is short of water.
Image: Lettuce planting
4. Scientific fertilization:Lettuce requires clay loam rich in organic matter with strong water and fertilizer retention. Lettuce likes slightly acidic soil, with a suitable soil pH of 5-7. For every 1000 kg of lettuce produced, it absorbs 2.5 kg of nitrogen, 1.2 kg of phosphorus, and 4.5 kg of potassium, among which head lettuce needs more potassium. During the growth period, nitrogen, phosphorus, and potassium fertilizers need to be used together. The plot for planting lettuce should be deeply plowed and carefully prepared. Before planting, apply sufficient base fertilizer: 3000-3500 kg of well-rotted farmyard manure per mu. After applying, plow deeply, water thoroughly to the bottom, and make beds after the soil dries.
5. Careful planting:The day before planting, irrigate the seedbed to moisten the seedling clumps. The next day, lift the seedlings with as much soil as possible to reduce root damage. When planting, first open furrows on the bed surface, 4-6 cm deep. On a 70 cm bed surface, plant 3 rows. After opening the furrows, apply 25 kg per mu of ternary compound fertilizer, then irrigate. After the water seeps in, place the seedlings at a plant spacing of 24 cm, cover with soil and close the furrows, rake the bed surface level, cover with plastic film, and guide the seedlings out through the film.
6. Post-planting management:Lettuce likes moisture and requires a sufficient water supply throughout its whole growth period. Water once with recovery water 5-7 days after planting. After watering with recovery water, for plots not covered with plastic film, carry out 2 rounds of intertillage, loosening the soil, and weeding. After that, water 3-4 times, and apply nitrogen and phosphorus fertilizer in stages along with watering, at 15-20 kg per mu. Stop watering before harvest to facilitate storage and transport.
Image: Lettuce planting
7. Pest and disease control:The main diseases of lettuce include downy mildew, soft rot, viral disease, and sclerotinia rot, among which sclerotinia rot and soft rot are more harmful. You can use crop rotation, appropriately reduce planting density, avoid overwatering, frequently shallow hoe and scrape, keep the soil surface dry, promptly pull out diseased plants, remove dead leaves and burn them in a centralized way. After the disease occurs, spray agricultural streptomycin and amobam. In hot, humid seasons, spray chlorothalonil once every 5-7 days for prevention. The main insect pests include aphids, thrips, and cutworms, which can be controlled with omethoate, fenvalerate, etc.
8. Scientific harvesting:Non-heading lettuce can be harvested at the appropriate time according to market prices. Head lettuce is best harvested after the head is firm; harvesting too early will affect yield, while harvesting too late will cause the stem inside the head to elongate, the head to loosen, and quality to decline.
[Editor's Concluding Remarks]Lettuce likes a cool environment and tolerates neither cold nor heat, so special attention is needed during cultivation. Above, we introduced the planting time and methods for lettuce. Have you all learned them?