To treat powdery mildew, gently remove any infected leaves and stems that have begun to show signs of damage and then apply a fungicide. Fungicides containing sulfur, neem oil or triforine may be effective at killing powdery mildew on healthy leaves, stems and buds.
Beside above, why does my succulent has white spots?
White spots on succulents is most often an indication of a fungal plant disease called powdery mildew. Relatively warm and dry conditions promote the growth of this fungus. … In other cases, white spots may be due to insect infestation, high salt levels, or it may just be a part of the plant’s own defense mechanism.