Anthracnose on dogwood

There are two distinct anthracnose diseases of dogwood, and the difference is not just academic -- one is primarily cosmetic, the other can kill the tree. Spot anthracnose appears every wet spring and causes small leaf spots that most dogwoods shrug off. Dogwood anthracnose, caused by a different.

There are two distinct anthracnose diseases of dogwood, and the difference is not just academic — one is primarily cosmetic, the other can kill the tree. Spot anthracnose appears every wet spring and causes small leaf spots that most dogwoods shrug off. Dogwood anthracnose, caused by a different fungus, attacks leaves, twigs, and branches progressively, kills stem tissue over multiple seasons, and has killed large numbers of flowering dogwoods across the eastern US since its appearance in the 1970s.

I don't grow dogwoods at my Long Island property, so this guide draws on University Extension and USDA Forest Service research.

Two anthracnose diseases: know the difference

Spot anthracnose (minor)

Spot anthracnose is caused by Elsinoe corni. Per Clemson HGIC, it produces:

• Small, circular spots 0.1 inch in diameter on leaves and flower bracts
• Tan centers with purple-red margins
• No significant tissue death beyond the spots

Spot anthracnose is cosmetically unpleasant in wet springs but does not kill branches or significantly weaken trees. Most healthy dogwoods tolerate it without treatment.

Dogwood anthracnose (serious)

Dogwood anthracnose is caused by Discula destructiva. Per Cornell Cooperative Extension, this disease was first identified in the eastern US in 1978 and has since killed millions of flowering dogwoods, particularly in the Appalachian region and the mid-Atlantic.