Did your roses look odd this past year — stems and leaves that stayed red all summer, or lots of stems or buds all bunched together? (Those bunches are called “witches’ brooms.”) If so, they could have rose rosette disease — a virus carried by a miniscule mite.
It may be just a small branch affected at first but rose rosette is a serious disease. It can infect and kill almost all types of roses and spread from plant to plant. What to do? Remember your IPM principles and scout! Inspect your roses often for first signs of the virus. Even wild roses can carry it, so look at those too. You can check this fall and if you are not sure, mark those plants to look at again in the spring.
Found symptoms? Remove symptomatic plants to keep rose rosette from spreading. It’s unlikely that pruning out infected parts will save your roses or keep the mites from hopping onto neighbouring plants to feed and infect them. And bag each plant right away! Don’t carry them through the garden dropping mites as you go.