Tips for Handling Dogwood Powdery Mildew

Dogwood powdery mildew is showing up in urban landscapes this spring. This disease is generally more common during drier weather, but cool nights have contributed to the development of this disease.

How do you tell if powdery mildew is affecting your dogwoods? Look for dusty, white patches of fungus growth which are generally more conspicuous on leaves and young shoots near the top of plants. Some affected trees also show a yellow mottling and distortion of new leaves, as well as yellowing of older leaves.

If powdery mildew is showing up in your dogwoods, what should be done about it? In most seasons, no control measures are necessary since powdery mildew won't kill plants. However, as a result of heavy levels of infection on landscape trees in some areas of the state this season, homeowners might want to start a dogwood powdery mildew control program. Under conditions of severe infection, powdery mildew is contributing to plant stress and reduced ability of leaves to carry out their job of photosynthesis.

The best way to control dogwood powdery mildew is to start a fungicide spray program. While application of fungicides won't cure the disease, fungicides will slow disease development and prevent infection of new leaves which are formed later this season.

The best results from application are achieved when applications are started at the first sign of powdery mildew infection.

Another way to help control dogwood powdery mildew is to avoid over-fertilization with nitrogen fertilizer next spring. Dogwoods with excessive and succulent shoot growth are more susceptible to infection by dogwood powdery mildew.

For more information about disease control in the home landscape, check with us at the County Extension Office.

Written by the late Dr. Frank Killebrew

Contact Information

Mississippi State University
Mississippi State, MS 39762

Main Telephone: 1-662-325-2323