I am the gardener for the city of Riverview and I also take care of my subdivision park. About 8 years ago we planted 6 burgundy wine Nine Bark. They have done well up until this year. They have a lot of die-off on them and 3 of them have a white powdery appearance on some of the leaves, but it doesn't look the same as a powdery mildew on lilacs. Any idea what I should do or do you think it will go away. The majority of the bush looks okay
Wayne County Michigan
They are stand alone bushes and get full sun. I have others throughout the city of Riverview but only the burgandy wine were effected. But I probably wasn’t as good as I should have been about pruning the old branches. I cut some of the mildewed branches (not all) and sprayed with a fungicide.
Some cultivars of ninebark are more susceptible than others to powdery mildew. This one could simply be one of the more susceptible cultivars.