The green leaves of watercress fall off as soon as they get dark.

Reasons for improper watering: watercress likes humid environment when it grows, but once it is improperly watered and over-watered, it will cause a lot of water loss in the soil, because the roots are difficult to breathe, which will lead to the gradual decay of the roots. Water temperature is also important. ...

Reasons for improper fertilization: Rational fertilization can promote the growth of watercress. Once too much fertilizer is applied, or undecomposed organic fertilizer is applied, the root system may be burned, making it difficult for plants to grow. Solution: Daily application. ...

Reason for high temperature: Douban doesn't like hot weather. High temperature in summer is not conducive to growth. At first, the intensity of light will lead to black spots. If the situation is serious in the later stage, it will directly cause decay. Solution: watercress is green in summer. ...

Reasons for low temperature: Not only because of high temperature, but also because of low temperature in winter. Solution: Be sure to move to a warm room in winter and keep the temperature at 10℃.