What is choy sum? Get to know this common leafy green vegetable
Choy sum, also known as caitai, is one of the specialty vegetables of southern China. It is currently mainly cultivated in regions such as Guangdong, Shanghai, Zhejiang, Jiangsu and Anhui in China.
Method for transplanting choy sum seedlings
1. In early spring, choose a greenhouse or cold frame to raise seedlings, and start sowing on March 25—30.
2. Seedbed: the bed width is 1.2—1.3 m, and the bed length depends on the terrain. Before making the bed, dig it over finely and rake it level, apply 5—6 kg of fully decomposed organic fertilizer per square meter, and add 50 g of crushed potassium sulfate-type compound fertilizer specially for vegetables and mix it evenly with the bed soil, rake it level and tread it firm, then sieve the covering soil and set it aside.
3. Sowing: choose seeds that are large, uniform and have a high germination rate. Before sowing, water first to moisten the bed, the sowing rate for wet seeds is about 700 seeds per square meter, after sowing cover with 0.3 cm of sieved fine soil, water thoroughly, and generally full emergence occurs in 2—3 days. When the weather is colder, you can sow after sprouting, and after sowing cover with plastic film or set up a small arched shed to keep warm and moist.
4. Check temperature and humidity promptly, and replenish water and keep warm in good time. If pests such as leaf miners and aphids are found, control them promptly.
5. Transplanting: raise seedlings for 20—25 days, and when the seedlings grow to the 2-leaf-and-1-heart stage up to 3 true leaves, they can be transplanted and set out. Raising seedlings and transplanting saves seeds; to plant 1 mu of field, only about 70 g of seeds are needed. For early-maturing varieties such as 45 and 49 choy sum, the planting spacing is 10 cm×15 cm; for medium-maturing and late-maturing varieties such as 60 and 80 choy sum, which have a larger plant type, the planting spacings are 15 cm×18 cm and 15 cm×20 cm respectively. If side shoots are to be harvested continuously after harvesting the main shoot, plant them a little more thinly at setting out.