Do your Ninebark, Peony or other dense-leaves shrubs have white stuff on their leaves? If so, you most likely have a fungal disease called Powdery Mildew.
Powdery Mildew is a fungal disease that is commonly found on Ninebark, Bee Balm, and other densely-leaved deciduous plants, especially when it is cool and wet. The disease is fairly cosmetic and tends to not hurt the overall plant health, unless left untreated for many seasons. However, it is still recommended to treat for it when your plants begin to show symptoms, in order to avoid long term damage.
If you notice any of these symptoms on your tree or shrub, send us a photo or bring in a sample for proper diagnosis.