Epidemic disease is the most likely cause of the blackening of its leaves. If we don't know whether the cause of this phenomenon is this one or not, then we can see the appearance of this disease. Generally speaking, most of the leaves of the plants suffering from the disease will turn brown and start to rot slowly, while the bottom of the stems will turn dark green, soft, brown and finally black. In addition, where the disease occurs, the leaves will wither, some of the tops will rot and may become dead heads.
The disease usually occurs when the humidity is high and will spread quickly. So once it is confirmed that it has this disease, we should pull out the diseased plant in time and increase the interval of watering. In addition, when cutting, we should also pay attention to the selection of branches without diseases and insect pests, the substrate should also be determined to be detoxified, the cutting should not be too dense, and the ventilation and light transmission should be determined well. We should drain out the water in time when it rains, otherwise the disease will happen easily. At the beginning of the disease, we can consider using metalaxyl or Cleo to control
The symptom of this disease is that there will be water stains or black spots on the edge of the leaves. When the disease is serious, it will attack the whole leaf. The way to treat it is to control the watering and fertilization, remove the diseased leaves and treat with chlorothalonil.