TROUBLE SHOOTING
ROSE ROSETTE DISEASE
Rose Rosette Disease is a problem that has been appearing in Western
Pennsylvania more frequently as time goes by. It is a plant disease that
is not yet fully understood but is thought to be viral in nature spread by a
wingless mite (Phyllocoptes fructphylus). Rosa Multiflora is particularly
susceptible to this problem and is like the rose stock that brought the
disease to the United States from Japan in the 1860's. Multiflora is not
considered a wild invasive plant and is very common in our area. The
good news, if any, about this problem is that it is not easily transmitted
from one bush to another. The bad news is that there is no effective
spray or other control that will stop the disease once a bush is infected.
What does it look like?
The common name for this disease is "witch's broom". These are cluster
of small, reddish colored distorted branches. This reddish pigment does
not fade. This is the way to distinguish this condition from the new
growth on many bushes. These branches will sometimes produce
flowers which are also deformed, often mottled and give the appearance
of a plant accidentally sprayed with a herbicide.
Control: Once a bush is infected with this disease the best treatment is
to dig it up and either burn it or dispose in a bag or container that will be
sealed. The transmitting mite may remain in the root stock. If you are
sure you have gotten all of the root of the bush out of the site you may
plant another rose. If not, it is probably best to replace the rose with
some other plant. If you do not remove the infected bush, there is a
good chance that the mite will be carried down wind to other roses. The
mite does not fly which is the main reason that the disease is slow to
spread to other bushes. But in time it will move through the rose garden.
For more information, follow this link to a detailed report on this problem
published by the Virginia Tech. Or see our December 2007 Society
Newsletter.
Virginia Tech Pulication on Rose Rosette Disease
Rose Rosette Disease is a problem that has been appearing in Western
Pennsylvania more frequently as time goes by. It is a plant disease that
is not yet fully understood but is thought to be viral in nature spread by a
wingless mite (Phyllocoptes fructphylus). Rosa Multiflora is particularly
susceptible to this problem and is like the rose stock that brought the
disease to the United States from Japan in the 1860's. Multiflora is not
considered a wild invasive plant and is very common in our area. The
good news, if any, about this problem is that it is not easily transmitted
from one bush to another. The bad news is that there is no effective
spray or other control that will stop the disease once a bush is infected.
What does it look like?
The common name for this disease is "witch's broom". These are cluster
of small, reddish colored distorted branches. This reddish pigment does
not fade. This is the way to distinguish this condition from the new
growth on many bushes. These branches will sometimes produce
flowers which are also deformed, often mottled and give the appearance
of a plant accidentally sprayed with a herbicide.
Control: Once a bush is infected with this disease the best treatment is
to dig it up and either burn it or dispose in a bag or container that will be
sealed. The transmitting mite may remain in the root stock. If you are
sure you have gotten all of the root of the bush out of the site you may
plant another rose. If not, it is probably best to replace the rose with
some other plant. If you do not remove the infected bush, there is a
good chance that the mite will be carried down wind to other roses. The
mite does not fly which is the main reason that the disease is slow to
spread to other bushes. But in time it will move through the rose garden.
For more information, follow this link to a detailed report on this problem
published by the Virginia Tech. Or see our December 2007 Society
Newsletter.
Virginia Tech Pulication on Rose Rosette Disease
Web Master: David McKibben dhmckibben@hotmail.com
Page was lasted edited on 12/2/92007
Copyright © 2007 Pittsburgh Rose Society All rights reserved
Pittsburgh Rose Society
The miniature climber, Jeanne
LaJoie, infected with Rose
Rosette Disease. Photo by
David McKibben, Pittsburgh
Rose Society
LaJoie, infected with Rose
Rosette Disease. Photo by
David McKibben, Pittsburgh
Rose Society