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Identification of Rose Rosette Disease (RRD) #752328

Asked May 26, 2021, 3:40 PM EDT

Based on internet research it appears that the knockout roses on our property are infected with RRD. Our landscaper believes that is the case. We took a sample to several nurseries and one said yes and the other said herbicide or cold weather. Because we believe we have it and the remedy is to remove the infected plants we would like confirmation prior to that step. I can bring cuttings to you if necessary. Please advise. Thanks,

Dorchester County Maryland

Expert Response

It's not fully possible to know for sure from afar but we don't think that your photos look diagnostic of rose rosette disease. New rose growth is often red and our plant pathologist noted that the production of full sized flowers and their opening makes it unlikely to be that disease.

We would wait on pulling them and watch for other signs such as witches brooming, etc.

Here is our page on Rose Rosette disease: 

https://extension.umd.edu/resource/rose-rosette-disease



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 May 27, 2021, 11:01 AM EDT
Hi Christine,

    Thanks very much for engaging.

    When I look at our plants they look like the ones in your pictures.  There is an obvious difference between them and ones that are not infected.  How can I send you, or bring you a sample so you can see it clearly?

Thanks,

Mike
The Question Asker Replied May 27, 2021, 11:23 AM EDT

We do not take samples and there is not a test we can do for it. Our plant pathologist reviewed your photos again. This looks like normal bud growth and flowering. Continue to monitor your plants for usual growth patterns like excessive thorniness and/or stunted stems that are closely bunched together.

Christa

Answered by the Home 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 May 28, 2021, 11:07 AM EDT

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