1、 Cause

1. Lack of nutrients: in the process of growth, if the required nutrients are not supplied in time, it will be malnourished and unable to absorb nutrients, so the upper leaves will naturally turn yellow

2. Lack of light: it is a strong positive plant, and the best growth environment is full Yang, so as to promote its growth and present a good state. In a dark environment for a long time, insufficient light will lead to yellow leaves and even falling off

3. Improper watering: unreasonable application of water will have an adverse impact on growth. It can withstand drought, but it can't withstand water logging. Both of these conditions will cause leaf yellowing

2、 Rescue method

1. When the weather is lower than 30 degrees, fertilizer will be applied, and cake fertilizer liquid can be applied once a week, so as to ensure green leaves and bright flowers

2. Give sufficient light in time, pay attention to the position of the pendulum, face the sun, and be able to contact the sun to synthesize the required nutrients

3. According to the growth condition of the plant from time to time, apply water appropriately, but the water should not be too much to prevent the burden on the root