Bedford Area Master Gardeners Association

Virginia Cooperative Extension

Rosette Disease

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The client brought in a sample from his rose bush, which has red color, distorted leaves and buds.

DIAGNOSIS / RECOMMENDATION

The problem was identified as rose rosette disease (RRD).  The recommendation is to remove  and destroy the bush along with soil immediately around it. [1]

ADDITIONAL INFORMATION

RRD is a very serious virus disease affecting all roses, including Knock Out roses.  It is of great concern because it is known to be lethal to the wild multiflora rose (Rosa multiflora), and it is potentially lethal to many ornamental rose species and cultivars. It has long been known that the eriophyid mite, Phyllocoptes fructiphilus, spreads the disease.  These mites are too small to be easily seen but are active from May through October. [1]  Early symptoms of the disease show up with new growth in the Spring, and June is a time when many homeowners notice the symptoms.  

Early symptoms include excessive thorniness (thorns are pliant not stiff), distorted flower buds, thin (strapped) leaves, thickened stems, and sometimes reddish stems.  Witches brooms (clustering of small stems) also can occur. [1, 2, 3]  While some of the individual symptoms may be confused with herbicide injury, the combination of symptoms helps to identify RRD.  Not all symptoms may be present on a particular plant [1, 4].  Infected roses likely will die within 2 years.

Early detection and cultural control are the main approaches to controlling this disease; there are no chemical controls and affected plants cannot be cured.  Multiflora rose is the main source of infection in most areas; removal of those plants within 100 yards of ornamental roses may be helpful [1].  Space plants so that canes and leaves do not touch each other to make it more difficult for the mites to move from one plant to the next.  Mites also can be carried by wind currents from infested roses to healthy plants downwind. [5]  Any affected roses should be removed and destroyed, including all roots, if RRD is found [1, 2, 6].  Roses should not be replanted back into the same area.  Only roses are affected, so other species planted in the area will not be affected by RRD.

SOURCE June 2019 From the Help Desk

BetsyB., Bedford Extension Master Gardener, Help Desk Coordinator

RESOURCE LINKS

All resource links live and accessed, May 7, 2019)

[1]  https://www.pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/450/450-620/450-620_pdf.pdf 

[2]  http://extension.udel.edu/factsheets/rose-rosette-disease-2/ 

[3]  https://extension.tennessee.edu/publications/Documents/SP806.pdf 

[4]  https://wilson.ces.ncsu.edu/2015/06/rose-rosette-3/ 

[5]  https://extension.umd.edu/hgic/topics/rose-rosette-shrub 

[6]  https://hgic.clemson.edu/factsheet/frequently-asked-question-about-rose-rosette-virus/ 

–A Bedford Area Master Gardeners Association (BAMGA) Publication–

Answers provided herein were based on specific situations and growing conditions.These recommendations may or may not be appropriate for all circumstances.For specific recommendations for your particular situation please contact your local Cooperative Extension Office.
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