Leaf spots may be seen on columbine. Destroy infected leaves at the end of the growing season. No chemical control is listed.
Crown rot causes the crown and stem to rot. The plant wilts and the stems and leaves dry out. Remove and destroy infected plants. Two fungi cause this problem one is Sclerotinia sclerotiorum and the other is Pellicularia rolfsii. The sclerotinia may be controlled with drenches of benomyl. No chemical control is listed for crown rot caused by pellicularia.
Root rots cause root system decay. Avoid soils known to be infested with Pellicularia filamentosa or Pythium mamillatum. No chemical control is listed.
Cucumber mosaic virus causes leaf mottling and stunted plants that fail to flower. Destroy infected plants and control the insects which carry the disease. No chemical control is listed.
Powdery mildew causes a white coating on the leaves. Use applications of benomyl or sulfur.