Seedlings should be refined before greenhouse vegetables are planted.

Gradually training the seedlings before planting vegetables in the greenhouse can improve the resistance of the seedlings to the adverse environment. After training, the cold resistance and drought tolerance of the seedlings were enhanced, and the slow seedling stage was short after planting.

The specific methods are as follows: gradually reduce the temperature in the seedling place 7-10 days before planting, control moisture, stop heating, gradually increase ventilation, gradually remove the covered grass curtain, and remove it completely 3-4 days before planting (finally make the temperature in the seedling place close to the conditions of the cultivation place). The temperature was controlled at 15 ℃ ~ 20 ℃ in daytime and 5 ℃ ~ 10 ℃ at night. Generally, do not water for this period of time, if the seedlings in some places wilt at noon, you can only pour less water in the wilted places at any time to make the seedlings slow down. Do not water too much to prevent seedlings from growing too high in humidity.

In the seedling refining stage, it is necessary to prevent the freezing injury of seedlings. We should always listen to the local weather forecast, and when there is a cold snap, we should do a good job of cold prevention and heat preservation at any time, enhance light, control moisture and apply fertilizer reasonably, and prevent snow water and Rain Water from seeping into the seedbed. If you open the curtain in the morning, you should pay attention to the changes of the seedlings. It is found that the seedlings have slight freezing injury. Less straw or straw curtains should be covered to weaken the light in the seedling raising place, and never make the temperature rise suddenly in the seedling raising place. When the seedlings return to normal, remove the grass curtain.