Answer: Several species of borers do attack dogwoods by tunneling under the bark. Signs of borers include swollen areas on the trunk, usually just above or just below soil line. You may also see some sawdust-like material around the holes or on the ground underneath the holes. However, they are not likely the cause of your dying dogwood. A leaf and stem disease called anthracnose has weakened and/or killed many dogwoods in the mid-Atlantic region. The symptoms include small, purple-rimmed spots or large tan blotches on the leaf, with the entire leaf eventually turning brown. Twigs may die back several inches, or all the way to the main stem. Trunk sprout production is stimulated by the disease. These suckers will be very susceptible to infection, so it's probably not a good idea to try to save those. Trees usually die 2 to 3 years after symptoms first appear. The fungus thrives in cool, moist weather, and since dogwoods prefer to grow in the dappled shade of larger trees, this can create cooler, more humid conditions than in full sun, increasing the disease problems. While this may not be the actual cause of your dogwood problems, your tree is obviously weakened and stressed by its condition. If it does not already have anthracnose, it will be susceptible to it in its weakened state.
Arborists are not recommending replanting native dogwoods (Cornus florida) at this time, but instead replacing them with similar but resistant trees. Such choices may be redbud (Cercis canadensis ), Cornelian cherry (Cornus mas) or Kousa dogwood (Cornus kousa). A resistant native dogwood variety called "Appalachian Spring" is also a possibility.
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