Thanks Valerie for that tip! I have been having a problem with PM on phlox that is really unsightly and ruin the blooms. Next year, I will start spraying them every two weeks with this mixture when they start to show buds.
With regards to peonies with powdery mildew at this time of year, I would just start pruning them off. They are starting to go dormant anyway. I have cut off foliage in August and have not seen a decrease in blooms the following year. Though I do apply a tbsp of bulb fertilizer to these in early spring.
