Two weeks ago at our Master Gardener training class Dr. Jim
Jacobi, an Auburn pathologist, discussed the many diseases–viral
and bacterial, etc. that can afflict our beloved plants. One of
those that really caught my attention was Rose Rosette disease.
This is not a new disease but due to the widespread use of
Knockout Roses in landscapes the plant pathologists are seeing a
huge rise in outbreaks of this disease. Knockout Roses appear to
be very susceptible to this disease. It is spread by a mite on
wild roses but the mites are finding our Knockouts and having a
field day. Symptoms of RRD are witches broom on the rose stem,
red pigmentation of new growth, and excessive thorns. Before you
completely panic, new growth on all Knockouts is red but when
you have RRD the growth stays red. Up in North Alabama hundreds
of roses were taken out of a park. There is no chemical to treat
this disease. The only way to rid your garden of it is to get
rid of the rose–root and all. Then throw it away, do not compost
it. The d