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Coneflower- aster yellows or e. mites? #878056

Asked July 20, 2024, 5:43 PM EDT

Weird green growths coming out of coneflower cones and also sort of spider-webby gunk within the cones of others. If it’s those mites, the sites I’ve read say I can just cut off the blooms. If it’s aster yellows, I need to pull the whole plant apparently . The leaves don’t seem particularly yellowing, maybe somewhat… Or could it be both?! Thanks!

Baltimore City County Maryland

Expert Response

The spider-webby stuff is not of concern- it looks like spider webbing or perhaps some caterpillar silk.
However, you are correct- the weird green growths on the flower heads are a clear, classic symptom (that comes before yellow leaves) of Aster Yellows disease. 
Here is our page with more information:
https://extension.umd.edu/resource/aster-yellows-disease-flowers/
You are correct that that particular plant should be dug out along with some soil margins, put in a bag and put in the trash.

I removed a diseased plant from a large grouping of them last year and have not seen it spread to others in the bed, so there is some reason to hope, at least so far.

Good luck.

Christine

Answered by theHome and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied July 22, 2024, 10:04 AM EDT
Thank you so much!!
On 07/22/2024 10:04 AM EDT Ask Extension <<personal data hidden>> wrote:
 
 
The Question Asker Replied July 28, 2024, 9:03 AM EDT
You're welcome. We are happy to help.
Answered by theHome and Garden Information Center (HGIC), University of Maryland Extension. For timely gardening information and tips, subscribe to our Maryland Grows blog and quarterly newsletter. Follow us on Facebook, Instagram, and YouTube. Replied July 29, 2024, 11:43 AM EDT

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