Diseases of Hosta sp.

Hosta sp. is attacked by two insects and slugs. Grasshoppers eat large irregular holes and black vine weevils eat notches in the edges of the leaves. Slugs eat small irregular holes. Use insecticides on the insects. Controlling the growing conditions is more useful for slugs (keep plants on dry side minimizes use of mulches). Anthracnose, sun burning, and drought stress are the other problems. Anthracnose causes brown lesions that may spread to encompass entire leaf. Sun burning often bleaches (light tan to whitish) the leaves. Drought stress usually causes dead leaf margins that may become infected with saprophytic fungi. Anthracnose cause brown spots on the leaves that can merge to form irrugular dead areas and occurs more often on hostas in wet or over watered locations.

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.