Heuchera sp. (Coral bells) get both fungal and bacterial leaf diseases. Pseudomonas causes "reddish" brown spots that may cause the leaf to distort. Xanthomonas causes small brown angular to circular spots with yellow halos. Anthracnose causes small brown spots. Botrytis causes large brown spots. In addition the plant is prone to sun burning when the plant is exposed to too much hot sun. The sun burning causes irregular bleached dead areas on the leaves.
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.