To combat the powdery mildew, transplant your peonies 4 feet apart from each other to provide good air circulation. Plant them in the sun: Sun mitigates the effects of powdery mildew. Next summer, use a fungicide spray every 7 to 14 days. This will help to keep the mildew at bay, but not to prevent it entirely.
Hi Karen,
To combat the powdery mildew, transplant your peonies 4 feet apart from each other to provide good air circulation. Plant them in the sun: Sun mitigates the effects of powdery mildew. Next summer, use a fungicide spray every 7 to 14 days. This will help to keep the mildew at bay, but not to prevent it entirely.