Leaf spot or leaf scorch on azaleas is caused by a fungus. At first, dark red to brown spots appear on leaves in early summer. Later these spots turn lighter brown, while the leaf turns yellow around them. The fungus can survive the winter on dead leaves or on infected plants in a greenhouse.

Management Options

Non-Chemical Management

Avoid overhead watering.
Space plantings to allow good air circulation so wet leaves can dry quickly.
Rake and destroy all leaves from beneath infected plants.
Plant resistant varieties. Your county extension agent or WSU Master Gardeners can make recommendations.

Select non-chemical management options as your first choice!

Chemical Management

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

None recommended

Images

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Caption: Rhododendron fungal leaf spot Photo by: R.S. Byther

WSU Extension

Hortsense