Now is a good time to inspect your roses for unusual growth. Rose rosette is a virus transmitted by mites which causes excessive thorniness, deformed flowers, and odd growth called witches’ broom. This virus has devastated both public and private gardens. There is no cure and the virus is fatal. Roses with rose rosette should be disposed of properly.
A website for reporting, roserosette.org, is sponsored by Texas A&M AgriLife, along with other universities and companies. The website also shows photos of rose rosette damage, and information on this disease. Reporting the spread of rose rosette is important. Cases have been reported from Massachusetts to California, with numerous reports in Texas. So far, there have been no reported cases in Henderson County, but there have been cases reported in Smith, Kaufman, and other counties nearby.
If you feel you may have rose rosette in your garden, please contact your County Extension Agent. Either a site visit will be made, or a confirmation given through the use of photos and phone interviews. Be aware that herbicide damage mimics some of the symptoms of rose rosette, so you will be asked about your and your neighbor’s use of herbicides. Other information useful to the Extension Agent is the year the rose was introduced into your garden, type of rose, and pruning practices. The mites are small enough to travel on the wind, however, they can also be spread by contact with tools and clothing.
Odd growth does not always mean rose rosette, however. Other types of malformed growth can be caused by numerous factors, including but not limited to: fasciation, chilli thrips, and odd weather. If you suspect rose rosette, it is best to get a confirmed diagnosis from the Extension Agent or someone knowledgeable about this virus.
It is important that roses with rose rosette be removed from your garden as soon as it is detected in order to keep the virus from spreading to surrounding roses. Watch newly purchased roses for odd growth, and inspect roses in your garden often.