1, the growing period of lettuce is generally about 40 days, lettuce like cool climate, seedlings can generally tolerate a low temperature of minus 5 degrees, the more suitable germination temperature of 15 ~ 20 degrees, lettuce seed germination takes longer, more than 4 degrees when the seeds can be slowly germinated, in the appropriate temperature and humidity environment, the germination time of about 3 ~ 4 days, if the temperature exceeds 30 degrees, germination will be slow, almost no germination. will be slow, almost no germination. According to the temperature requirements of lettuce, summer is obviously not suitable for the growth of lettuce, generally arranged in the spring and fall sowing, planting should be low-temperature treatment should be carried out before planting, can be converted into the seed of the material, enhance the enzyme activity within the seed, winter planting can be used to protect the ground cultivation, to meet the needs of the annual supply of the market, the lettuce spring sowing in about February to April for seedling, the fall from the second half of July to the second half of August for Sowing seedlings, planting non-bearing lettuce in the home garden, time requirements are not so strict, fall sowing time can be extended to mid to late September.

2, knotting lettuce in the temperature is too high when not suitable for growth, knotting ball lettuce in 11 ~ 18 degrees, suitable for stem and leaf growth, into the knotting period, 17 ~ 18 degrees is the more suitable temperature, the phenomenon of non-knotting is because the temperature is too high, more than 21 degrees of lettuce is not easy to form a knotting ball, if the temperature exceeds 30 degrees, it will happen to the growth of the poor, it is necessary to pay attention to the attention of avoiding the Hot summer, when planting lettuce, to master the characteristics and growth habit of lettuce.

3, different varieties, different regions of lettuce planting slightly different, such as spring and summer to choose some of the more heat-resistant varieties, fall and winter to choose to plant the ball lettuce varieties, but also to choose the loose leaf type lettuce varieties.

4, lettuce can be live or seedling transplantation, planting density is generally 20 centimeters between rows, plant spacing of 10 to 12 centimeters or so, before sowing, the seeds should be low-temperature treatment for about 48 hours, when the seeds have dew white, can be sown.