Knowledgebase
Treating Powdery Mildew on my Peonies #863465
Asked April 05, 2024, 2:12 PM EDT
Seeking the best treatment options for powdery mildew on my peony plants. They are planted in an area which receives mostly sun in the back of my property. The soil seems to be quite clay based, so unless we have gone at least 10 days with 85+degree temperatures and no precipitation, I don’t water the plants, yet they still seem to suffer from this fungal pest.
I am grateful for any “home remedy” or commercial fungicide recommendation that is also safe for the many birds, rabbits, squirrels, other rodents, raccoons, and deer that live near our property.
Kent County Michigan
Expert Response
Hi Kelly,
You have a few things that you can do to help with powdery mildew on peonies.
Ensuring good air circulation can help to reduce a humid environment where powdery mildew likes to get established.
You can reduce the fungal spore load by cutting out and removing any affected foliage. Be sure to sterilize your equipment when done to reduce spreading.
Cut back foliage and remove from garden at the end of the growing season. Bag and dispose, do not compost affected plants.
This is an answer from a previous 'AskExtension' question about PM in peonies in a different Northern state, but same concerns, that you may find helpful. https://ask2.extension.org/kb/faq.php?id=841512
"If your peonies are done growing, you can prune them and remove any infected material. Be sure to wear disposable gloves and sterilize your cutting utensil after.
You can also try neem oil, horticultural oil, or sulfur-based fungicides. These are more organic and will help. Applying these early in the growing season, before blooms appear will help as well.
Monitor any peony plants left and if they become infected, prune them back."
Thank you for your peony question.
Jean P.
