This time of year some peony bushes get infected by a fungus commonly called powdery mildew. The disease will not normally kill your peony bush in one season, but could if left uncontrolled for several years. Powdery mildew is more prevalent in shady areas and when plants are closely spaced.

Here are some solutions to stopping the powdery mildew from returning next summer:

  1. If the area is shady – try to trim some of the lower tree branches to allow for more sun and air circulation.
  2. Remove and throw away all dead leaves now and in the fall to prevent the disease next summer. Diseased leaves should not be composted.
  3. If the plants are closely spaced – divide and replant the plants to allow for more space and better air flow.
  4. Watch the plants next summer and spray a fungicide like Liquid Copper at the first sign of powdery mildew.
  5. Fertilize your peony plants next spring with Earl May Garden & Plant Food Plus, so they have the strength to fight these summer diseases.