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Aug 20

Common Pest Problem - Powdery Mildew

Posted on August 20, 2018 at 10:14 AM by Colin Heyne

 Powdery Mildew on twigs
 Powdery Mildew on leaves
 Powdery mildew on twigs
 Powdery mildew on leaves

Powdery mildew is a common fungal disease that affects many types of plants. Each species of fungus is linked to specific plants instead of being generalists like many other plant diseases. Generally speaking, powdery mildew is not a serious problem and early detection and identification can keep damage to a minimum.

The time when powdery mildew is most visible is late summer and early fall, where it will appear as white or gray powdery growth on the top surface of leaves, stems, flowers, and fruit. These fungi do not require moist conditions to establish and grow and, as a result, tend to thrive in our local climate. 
Species commonly impacted are: Alder, Birch, Catalpa, Dogwood, Elm, Magnolia, Oak, Crape Myrtle, and London Plane. The key to management is addressing things early. For more information on powdery mildew and possible treatment options visit the University of California IPM website.