This is a disease for plants and especially for leafs. A sort of black spots will appear on leafs. This is caused purely by the germs and fungal infection for the plant. These infections for the plants are highly possible in winter season. With the help of germicides we can protect the plants from this disease.
The black eyed Susan is a perennial flower that can attract any number of diseases. The most common is a fungal disease, Septoria, that causes small black lesions on leaves.