Characteristics

• Peonies are spring-blooming perennial shrubs with large, fragrant blossoms lasting about a week. You can extend the bloom season to six weeks by planting early, mid-season and late varieties. Peonies thrive in USDA Zones 2 to 8, when planted in full sun and well-drained soil rich in organic matter.
  
  

Diseases

• Botrytis blight and phytophthora blight are fungal diseases that attack the buds and then the stems and leaves. Fungi and viruses can cause spotting or curling of the leaves. Verticillium wilt and white mold are soil-borne fungi that cause severe wilting.
  
  

Prevention

• The best way to prevent diseases is with good cultural practices and sanitation. Space plants so air circulates around them freely. Water early in the day, and never get the foliage wet. Remove spent blossoms and infected parts of the plant right away; disinfect pruners with 70 percent alcohol between cuts. Destroy plant debris rather than composting. Fungicides applied early in the season can help prevent diseases.