Leaf Spot on Azalea and Birch

Identification

• A number of fungi cause leaf spots to start appearing on foliage of birch and azaleas. Leaf spot diseases are mostly aesthetic in nature and generally do not cause long-term damage to the plants.

Damage

• Leaf spots range in size from very small dots to raised, yellow to brown patches on affected leaves. The older azalea foliage is, the more prone it is to leaf spots. Symptoms are pronounced during fall and winter. Heavy infection leads to premature leaf drop. Extensive leaf spot infection in birch trees also leads to premature defoliation.

Management

• Keep plants clear of fallen foliage and debris. Avoid the use of overhead watering, as this keeps foliage wet for prolonged periods. No fungicidal control is recommended for azalea leaf spots. Spraying birch trees with copper-based fungicides and Bordeaux mixture helps minimize chances of infection.