Azalea: Ovulinia petal blight

categories: Azalea Azalea Diseases Ornamentals Shrubs

revision date: 2024-06-05 02:07

Azalea Ovulinia petal blight on pink flower.
Azalea Ovulinia petal blight
Photo by: R.C. Linderman


Ovulinia petal blight affects the flowers only (not leaves or shoots) of azaleas and rhododendrons. Infected flowers first display small, water-soaked spots which enlarge quickly. The petals quickly become slimy and turn brown, sometimes within two or three days after fully opening. The infected blossoms remain on the plant and later provide a source of infection for next year’s flowers. Flowers on lower branches are affected first. The disease overwinters in dead flower material or top layers of mulch, and is favored by high humidity.

Management Options

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

Non-chemical Management

Select non-chemical management options as your first choice!

  • Remove and destroy all infected flowers from plants and from the ground.
  • Remove top inch of soil or mulch from beneath infected plants and replace it with clean material.
  • Avoid overhead watering.
  • Space plantings and prune to provide good air circulation in and around plants.

Chemical Management

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

  • Apply protective fungicide just before budbreak and then at recommended intervals during bloom period.

Approved Pesticides

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.