Answer: Peonies are subject to several types of infection both in their blooms and on the stems and foliage. Often, rainy weather will make the problem worse. Good sanitation is important in controlling these problems and a careful clean up of all peony debris each fall goes a long way, as does a careful deadheading of the spent blooms and any spots that occur early on in the season. Be careful not to work on the plants when they are wet, avoid overhead watering, and provide ample room for each plant so as to maximize air circulation. You might also wish to use an appropriate fungicide; your county extension should be able to identify the specific problem and recommend the best treatment for it.
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