Small rape is the name of the north, and the south is generally called Chinese cabbage or cabbage, and Shanghai Haiqing is one of the small varieties. There are no big vegetables, but it may be Shanghai green, which is bigger and older.

1, Variety: Vegetables cultivated in spring should be selected with strong winterness, so as to avoid bolting. Generally, varieties such as March Slow, April Slow and May Slow are selected in Shanghai.

2. Seedling raising: Make the land for seedling raising into a border with a width of 2m (even ditch), and use decomposed organic fertilizer1000kg per mu. Sow in the first ten days to the last ten days of 10, with a seed dosage of 0.3kg per mu. Sow evenly and be practical after sowing. After emergence, the seedlings should be interplanted for 2 ~ 3 times, and appropriate topdressing should be applied. When the seedlings have 6 ~ 7 true leaves, they can be planted in the field.

3. Land preparation: After ploughing in the field, apply 50 kilograms of compound fertilizer special for vegetables per mu as base fertilizer, and make a border with a width of 2.5 meters (even ditch) to be planted.

4. Seedling cultivation in greenhouse is slow in March and planted in late 1 month, and slow in May from early February to late March. The row spacing of plants were March Slow10×15cm, April Slow15×15cm and May Slow15× 20cm respectively.

5. Field management: topdressing once after planting live trees, and applying 5 kilograms of urea per mu. Apply it for the second time before the bank is closed, and apply 7.5 kilograms of urea per mu. Pay attention to prevent aphids in March.

6. Harvesting: Harvesting in open field in March is slower than in late February to late March, harvesting in greenhouse in April is slower than in late March to early April, and harvesting in May is slower than in late April to early May. Remove the roots with a kitchen knife, and clean vegetables will be on the market.