Lettuce is also known as lettuce, divided into leaf lettuce and stem lettuce, which is more common throughout the country, and the lettuce varieties selected in different regions and different cultivation purposes are very different, and the sowing and harvesting periods will also be different. So, can we still grow lettuce in November?
If the temperature is not lower than 4 ° C, lettuce can be sown in November. According to the biological characteristics of lettuce, the temperature determines whether seedlings can emerge. The suitable germination temperature of lettuce is 15-20 ° C, more than 30 ° C, the seed germination is difficult, or the growth is poor, the temperature is too low to germinate. After the emergence of seedlings, it has strong low temperature resistance and can safely survive the winter in the environment of -5--6 °C. Seeds cannot be sown when the temperature drops below 4 °C, otherwise it will cause seed rot or germinate only in the spring of the following year.
In the area south of the Yangtze River, lettuce can be sown in November, and in addition to harvesting seedlings, leaf bulbs can also be harvested in early spring. Leaf lettuce cannot be planted except when the temperature drops below 4 °C or the summer temperature is above 30 °C, and can be sown at other times.
In temperate regions, lettuce cannot be sown in November. Overwintering stems can be cultivated in greenhouses in the north using lettuce, sown in mid-to-late September to early October, and generally colonized from late October to November, with a seedling age of 4 to 5 leaves. After the fleshy stem begins to expand, it keeps the daytime temperature 18 ~ 20 ° C, and about 10 ° C at night, which can be supplied to the market around the Spring Festival. The Yangtze River Basin can be cultivated in the open field, or it can be cultivated in the mulch film, and it can be marketed after the opening of spring. In South China, it can be covered with mulch film planting and supplied to the market before the beginning of spring.
If the small arch shed is used to raise seedlings and transplant in early spring, it is also possible to sow lettuce for stems in November in the Yangtze river and Huai River basins. Lettuce for overwintering stems planted in the open field requires seedlings to grow to 4-5 leaves before winter, and can quickly grow leaves in the spring, producing thick stems in time, and sowing too late will cause stalk yield and quality to decrease.
Conclusion: In temperate regions, the ground temperature in November gradually decreases to below 4 °C, do not sow lettuce for sowing stems, in the Yangtze River Basin, lettuce can be planted, and the slow seedlings can be completed before the soil freezes, which can produce new root systems. Cover the decomposing farm manure or crop straw before and after the soil freezes, and if possible, it can be covered with arches, and it can also be grown as usual in winter.