Azalea: Botrytis petal blight
Photo by: R.S. Byther
Biology
Botrytis petal blight is a fungal disease typically found in early spring.
Symptoms of infection include brown, water-soaked spots on the leaves, and masses of gray-brown spores which form on infected tissues.
Botrytis petal blight often occurs after the plant is injured or stressed.
Management Options
See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.
Non-chemical Management
Select non-chemical management options as your first choice!
- Good air circulation is essential. Space plantings to reduce humidity and allow good air flow.
- Avoid overhead watering.
- Prune out infected tissue, making cuts into healthy wood and disinfecting pruning tools between cuts.
- Clean up and destroy any diseased material beneath plants.
- Remove faded flowers and yellow leaves from plants.
Chemical Management
IMPORTANT: Always read and follow label directions when working with pesticides.
For more information on using pesticides visit :
Application interval varies by label. Best when used with cultural controls. Copper and chlorothalonil products may discolor blooms.
Approved Pesticides
If you choose to use a pesticide, some examples of products that are legal in Washington are listed below. Some products are labeled for just INDOOR or just OUTDOOR use, or may allow both uses. Be sure to choose a product appropriate for your situation. Always read and follow all label directions.
WSU Extension programs and employment are available to all without discrimination.
Evidence of noncompliance may be reported through your local Extension office.