8 - 13 - 2012
Rose Rosette….sad for any of us who love to incorporate roses into our gardens as there is possibly a catastrophic disease spreading throughout America attacking old and new roses alike.
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 of the disease –
• The plant's leaves will turn red in an irregular pattern. Eventually they will become deformed and brittle.
• Many deep red, succulent new shoots will suddenly emerge.
• The plant will be much more frost tender.
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.
The virus is spread in 2 ways:
• By grafting.
• And by a wingless mite that blows about on the wind.
The nearly invisible eriophyid mite will infect new plants between May and mid July in the U.S.
What to Do If Your Rose is Infected -
• 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:
o Plant cultivated rose bushes as far from known stands of multiflora as possible
o Treat the plants with Sevin, insecticidal soap or horticultural oil sprays weekly during the summer months to control the mites that spread rose rosette.
Top Things to do in August
• Pray that Rose Rosette does not come to your garden.
• Water – of course!
• Move pots and baskets to the shade to give them a break from the sun and heat.
• Cutback things that have lots of brown leaves…like spirea or perennials…remove dead plants – your beds and pots will look better.
• Drive around and look at gardens that are performing well in these extreme conditions.
• Look at how your irrigation system is performing – you may want to modify coverage this fall.
• Look forward to September – and the break in the “heat dome”.
Happy Gardening -
All My Best -