1、 Diseased insect

There are few diseases and insect pests of Pennisetum and its adaptability is very strong, but family breeding will inevitably be invaded by pests on other plants. For diseases and pests, we must find the source. The plants with serious diseases should be uprooted. The plants with mild diseases can be properly pruned, and we should pay attention to spraying medicine, which can be effectively treated

2、 The light is too strong

Pennisetum is a plant that doesn't like light very much. If the light is too strong, the leaves of the plant are easy to be sunburned. At this time, there will be black spots and may be withered and yellow. Generally, you need to put the plant in the semi shade and let it receive the scattered light. If it is summer, be sure to avoid direct sunlight, and increase the light in winter

3、 The temperature is too low

The cold tolerance of Pennisetum is not very strong. Once it is frostbitten, the plant is also easy to grow poorly, and black spots may appear on the leaves. In winter, be sure to put the plant in a warm place, or cover its upper part with plastic tape, which can also have the effect of heat preservation. Several holes should be pierced in the bag to ensure good ventilation and ventilation

4、 Too strong fertilization

Copper coin grass has a high demand for fertilizer, but the fertilizer must be thin and applied frequently. If the fertilizer concentration is too high, it is easy to burn its roots and cause black spots on its leaves. Usually wash the fertilizer in the soil with clean water. If the situation is serious, you can also change the pots and soil for the plants and put them in a cool place for preservation and maintenance