The main reason is water, temperature, humidity and ventilation. Especially in summer, if the water is too much, the moisture content of the soil will increase. Before the water is discharged, the root will rot, which will cause mildew. Some succulent plants don't need much water themselves. There are also the reasons for the long mildew is that the surface dust of the succulent plants is too large, or there are pests in the secretion of juice on their leaves, which will also lead to the long mildew of succulent plants.
In order to prevent the growth of moldy spot of succulent plants, it is necessary to reduce the amount of rainwater it receives. When watering, it is also necessary to control the amount of water, which should not be too much. Also put the succulent plants in a well ventilated place. If there is mildew at the root, it is better to replace the whole basin soil to eliminate the disease. At the same time, remove the places with mildew and continue planting. If it happens on the leaves, it is necessary to remove the whole leaves and put an end to its infection. It can also be used in places with mildew to kill bacteria. Try to let the succulent plants grow in a well ventilated environment. No matter the soil or the surface of the leaves, there should be no water accumulation, and proper amount of light
