Dogwood tree anthracnose

Asked September 14, 2019, 2:22 PM EDT

Hi, My dogwood tree has anthracnose and I know I need to dispose of the leaves and spray the tree. My questions are: when do I spray it? is there an organic option to that spray? When is the best time to trim branches on a dogwood tree? Thank you, Holly

Clackamas County Oregon

1 Response

Dogwood trees (Cornus species) may have leaf problems including Anthracnose. This information (link following) from the PNW Handbook gives homeowner and commercial chemical options. The boxed H is homeowner. Certified arborists may have other options. The timing of spray, as quoted in the handbook, is a preventative measure when fungal spores are moving, and does not stop the disease once the leaf is infected. “Begin sprays at budbreak and continue at 10- to 14-day intervals until dry weather. Applications the rest of the growing season may be needed if periods of wet weather occur and there are infected leaves or twigs on the tree.” The handbook also gives cultural control steps, and additional cautions. Always follow chemical labels. An additional caution is to be very sure you have the correct diagnosis before treatment. Dogwoods can have leaf scorch and other problems.