things can happen to good plants ó even when you
carefully tend to them.
a sad fact that gardeners ó and garden centers ó
deal with year in, year out.
how it is with Andersonís Home and Garden Showplace in
garden center is selling no roses to customers and
showcasing no roses in its display beds this season
because of a deadly virus called Rose Rosette Disease.
have ripped out over 250 Knock Out roses in our parking
lot to date that have been affected with the
disease," says Jason Blanchette, vice president.
act alone convinced Jason that it would be unfair to
sell roses of any kind to consumers who may experience
the same fate. Jason says he knows of more garden
centers nationwide that are abandoning roses. Other
garden centers in southeastern Virginia continue to
offer roses because they have noticed no severe
outbreaks or complaints from customers.
rosette disease has been spreading through much of the
wild rose population in the Midwestern, Southern and
Eastern United States for years, according to research
by Chuan Hong, a plant pathologist with Virginia Tech.
Recently, itís been confirmed in cultivated roses ó
Knock Out, Drift and Flower Carpet roses, to name a few
popular types ó in Virginia and other states. You can
read his report at http://pubs.ext.vt.edu/450/450-620/450-620_pdf.pdf
received some rose rosette disease samples last year but
nothing serious," Hong says.
sure, this disease is on the rise and we need to pay
more attention to it."
disease, first documented in 1941, is traced to the
multiflora rose, which came from Japan in 1866 as a
common rootstock for ornamental roses. Unfortunately, it
was found that multiflora roses are bad because a single
plant can produce a million or more viable seeds per
plant; over time, the roses have become known as
invasive weeds with enormous disease problems. Today,
new roses like Knock Out and Drift roses are grown on
their own rootstock.
Roses and Plants by Conrad-Pyle, developers of Knock Out
and Drift roses are putting extensive research into the
problem, according to Steve Hutton, company president.
They hope some of the native roses will provide
disease-resistance answers. A frequently-asked document
about the issue is found on its website at .
of the U.S. species with resistance to Rose Rosette
Disease are Rose palustris, R. arkansana, R. setigera
and perhaps a couple others," he says.
disease can infect any modern rose such as hybrid teas.
Seems like anything with Asian roses in its background
is susceptible ó again, this is a theory, not yet
mites spread Rose Rosette Disease, and no effective
controls are available for existing infected roses. Itís
not a soil-borne problem, but some suspect root-to-root
contact can help spread the disease because so many
shrub roses are being used in mass plantings. Good
sanitation ó picking up dropped rose petals and
foliage ó can help prevent it and other plant
problems. Pruning is also crucial to keeping the problem
away or under control ó roses should be pruned late
characteristics include witchesí broom growth, or
clustering of small branches, as well as reddening,
distorted, stunted and elongated leaves.
Elegance rose production in Minnesota has seen no rose
rosette so far, but the virus has moved into northern
Iowa, which has impacted some of southern Minnesota,
according to a company spokeswoman.
itís found, our expert recommends doing a hard cut
back on the plant, all the way to the ground ó that
way the plant can produce enough vigorous growth to not
express the disease," says Kathleen Hennessy.
didnít recommend spraying the plant with a miticide
rose experts recommend a drastic plant-removal process.
a big trash bag, dig up the plant, tie the bag firmly
shut and dispose of it," says Barbara Gelzer, a
horticulture volunteer with the organic rose garden at
the Virginia Zoo in Norfolk, Va. Sheís been growing
roses since she was 8 years old, having had a collection
of more than 200 plants in Ohio in the 1970s. The zoo in
Norfolk lost its entire 70-plant Knock Out hedge to the
disease, as well as many Flower Carpet roses.
mites may be gone at this point but donít take a
chance. Go back and remove every bit of root you can
find. Donít replant a rose in that spot. Watch all the
roses both nearby and downwind from the infected plant
for the next year or two."
is the best strategy, according to plant pathologist
Hong. Buy healthy plant material, he advises, and
fertilize and water plants as needed to keep their
pruning is an important part of rose maintenance, thus
itís advisable that people periodically sterilize
their pruners and other tools to reduce local disease
spreading," he says.
including myself love roses, and roses will continue to
be an important component in home yards. A way forward
is for rose societies, the public and science community
to work together to find more effective control options
for this growing disease problem."
you want to avoid the problem totally, there are many
other flowering shrubs that will provide months of color
in place of roses, including Encore azaleas, butterfly
bush, abelia, spiraea japonica, hydrangea paniculata,
rose of sharon and tropical oleander.