Mainly distributed in China, Nanjing and Shanghai are the most cultivated, so it is also called Shanghai Green. But also like cold, not high temperature, like light, strong adaptability to soil. It is one of the main vegetables in winter.

The optimum temperature for seed germination is 20-25℃, the optimum temperature for seed growth and development is 15-30℃ 1-3 days, and it can tolerate the low temperature of -8- 10℃ and be above 25℃. Vegetables damaged by light, rain and weak light are easy to cause overgrowth, elongation of stem nodes and degradation of quality. At the peak of growth, the collapse of vegetables requires sufficient fertilizer and water, with more nitrogen fertilizer, followed by potassium fertilizer and the least phosphorus.