JUST ASK: Why are the dogwoods dying?

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 Any idea why so many dogwood trees in the area are dying?


According to The Land Steward website http://www.landsteward.org, flowering dogwood trees are dying from anthracnose, a disease caused by a fungus.

According to the website, “the first sign of infection can often be seen on the leaves, where you might see tan spots that develop purple rims. Leaves may also have necrotic veins and leaf margins, and large necrotic blotches.

Another indication is what's known as twig die-back, and this in turn often results in the appearance of succulent shoots on the lower trunk and main branches of affected trees. On the trunk and limbs, you might see cankers and lesions with purple or reddish borders. Split bark and swellings often are external indicators of these cankers.

The infection appears to be aided by cool, wet weather, and infection seems to worse in trees growing in shaded or high-humidity areas ….

A fungicide such chlorothalonil, mancozeb will protect against leaf infections and needs to be applied before symptoms appear. Dogwood trees planted in a sunny, open environment are less susceptible to the effects of the infection.”

Two varieties of dogwood that appear to be resistant to the fungus are Appalachian Spring and Kousa.

More information is available through the USDA Forest Service website http://www.na.fs.fed.us/spfo/pubs/howtos/ht_dogwd/ht_dog.htm.