How do you treat spots on peony leafs?
I would take off all the affected leaves and destroy them. Then I would treat with a product made by Hi-Yield called “copper fungicide”. The copper has activity against both fungi and bacteria. You may need to re-treat in 7-10 days. Then I would watch the new growth for symptoms of the disease and treat as necessary. In the fall, cut all of the old plant material off and destroy. The new growth next spring may need to be treated early in the season to prevent the disease from showing up. I hope this helps. Good Luck.
