Rhododendron: Gray blight

categories: Ornamentals Rhododendron Rhododendron Diseases Shrubs

revision date: 2022-12-05 12:00

Rhododendron gray blight on leaves.
Rhododendron gray blight
Photo by: R.S. Byther

Biology

Gray blight is a fungal infection of the leaves. It usually becomes established after an injury to the leaf, such as sunscald, frost damage, or some mechanical injury. White spots or blotches with dark margins can be found on the leaf surface. On cut leaves, the infection may spread from the edge of the wound into the leaf tissue.

Management Options

Use Integrated Pest Management (IPM) for successful plant problem management.

Non-chemical Management

Select non-chemical management options as your first choice!

  • Place plants to reduce injury from sunscald, frost, etc.
  • Infection spreads quickly between cuttings. Do not propagate diseased plants.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

  • None recommended