Rose rosette disease is a viral rose disease spread by a tiny insect. The virus is specific to roses with Rosa multiflora being its primary host. Symptoms and treatment of rose rosette disease.
Picture of the witches' broom effect produced by rose rosette.
The disease is sometimes called witches' broom because of the way it causes new shoots to grow straight up and close together in broom-shaped clusters.
Rosa multiflora being the rose most vulnerable to this disease, will exhibit the most severe symptoms.
Other rose varieties will most often exhibit thickened stems displaying many more thorns than usual when infected with the virus.
A Hybrid Tea rose flower stem infected with rose rosette photographed beside a healthy stem.
The virus is spread in 2 ways:
The nearly invisible eriophyid mite will infect new plants between May and mid July in the U.S.
Rose rosette is not a common rose disease outside of Rosa multiflora's range.
Map showing the distribution of Rosa multiflora in the U.S.
R. multiflora is a thorny shrub whose arching stems bow down with heavy clusters of white to pink inch wide single blooms each summer. The fragrant flowers are followed by red hips which decorate the attractive plants all winter.
It grows into a thicket and is considered a noxious weed in some areas because of its tendency to choke out other species.
It was brought to the United States from Japan in 1866 to be used as a rootstock. It became widespread in the 1930s when the U.S. Soil Conservation Service recommended it to farmers as a good hedge rose to corral animals and prevent soil erosion.
So strong was their belief in the benefits of planting this wild rose that the agency gave away free rooted cuttings of it to anyone who wished to plant it!
Today, many states would like to be rid of the Multiflora rose. Rose rosette disease is being studied as it has proven to be devastating to this species.
The problem is that it sometimes spreads from R. multiflora to cultivated roses in nearby gardens.
Shovel prune it.
There is no cure for this virus. The infection will kill a small rose bush within 2 years. A large rose may survive for as long as five years. But if you allow an infected plant to remain in your garden you risk the virus spreading to your healthy roses.
There is no treatment but you can prevent your roses from becoming infected in the following ways:
Return to Preventing Common Rose Diseases
Preventing common rose diseases. Treatment of rose bush diseases. Rose plant diseases in Florida. Downy mildew, powdery mildew on roses, rose rust disease, black spot rose bush disease, rose rosette disease.
Double Delight Rose
HT Double Delight rose flowers are powerfully fragrant and very large. Double Delight roses are a colorful blend of red, cream and pink. A Double Delight Hybrid Tea rose bush can reach 6 feet in height.
Photo credit for the map and rose rosette images on this page goes to: James W. Amrine Jr., West Virginia University, Bugwood.org