Black Spots on Rudbeckia
How can I get rid of the black spots on the leaves of my black-eyed Susans? The spots grow until the whole leaf turns black. How do I keep it from spreading? Is there a way to get rid of them, and how do I prevent them in the future?
Certified GKH Gardening Expert
This sounds like black spot fungus. You can treat the plants with a fungicide and it should take care of the fungus. If you are manually watering them, try to water them from below rather than from above. The fungus is made worse by water sitting on the leaves.