Yellow asters disease
I live in Evansville. Some of my Black Eyed Susan plants and Purple Coneflower have been afflicted by what appears to be Yellow Asters disease. It is my understanding this is caused by a bacteria that is carried by a particular leaf hopper. I am pulling and disposing of the diseased plants. Are you seeing much of this in Vanderburgh Co.? Will this be an ongoing problem? Any info appreciated.
Thank you for your question to eXtension. As it so happens, I am your local extension educator in Vanderburgh County. I invite you to save my local email address (LCaplan@purdue.edu ) so that you can receive faster answers in the future.
I am definitely seeing aster yellows in the Evansville area, but I can't really say that it's at an epidemic level. None of my wife's flowers are showing symptoms, but I have seen it at several local private and public gardens.
Pulling and disposing of infected plants is the recommendation I would make. Trying to prevent it by spraying for the leafhoppers is extremely difficult, and would require much more insecticide treatment on flowering plants than I am comfortable with recommending.
A good article on this disease can be found on the Missouri Botanical Garden website: http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advi... .
Please let me know if you have any other questions.