Mature spots may have a white center.Though Marsonnina and Septoria leaf spot can look severe, it is mostly aesthetic and rarely fatal. Still, it’s wise to control the fungus.

Leaf spot happens a lot this time of year, especially when the weather has been damp and rainy or flat-out humid. Although it can look pretty bad, septoria is primarily a cosmetic issue.

Your photo and description indicate Septoria leaf spot, which is very common on Rudbeckia and is prevalent in Illinois. The disease begins on lower leaves and progresses up the plant but does not ...

As they do, the leaf turns yellow and eventually dies. This is due to a common tomato disease called Septoria leaf spot, caused by the fungus Septoria lycopersici.