Diseases of Echinacea sp. (Coneflower)

Echinacea sp. (Coneflower) may get Pseudomanas or Xanthomonas leaf spot. Both are bacterial diseases. Sanitation is the main control for these leaf spots. Powdery mildew will also occur under the right weather conditions. Botrytis may also occur. May get brown dead areas as well as distorted leaves. These plants now get aster yellows. The disease causes a witches broom in the flower head, greening of petals sometimes, stunting and possible death of the plant. Infected plants should be destroyed. There is an eriophyid mite that causes the flower to develop lumps or bumps or leaf like structures growing out the side ç remove infested flowers and destroy them. (Note that the aster yellows and the mite can cause similar looking distortions if not checked closely.)

Check with your local University of Illinois Extension office or garden center for current pesticide recommendations.

Written by James Schuster, Extension Educator, Horticulture, and reviewed by Bruce Paulsrud, Extension Specialist, Plant Pathology and Phil Nixon, Extension Entomologist, University of Illinois at Urbana-Champaign.