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Common Dogwood Diseases: Symptoms, Causes, and Management

Dogwood Disease Overview

Flowering dogwood (Cornus florida) and other Cornus species are affected by several significant diseases. The following table summarizes key diseases, their symptoms, pathogens, and management strategies.

Disease	Symptoms	Pathogen/Cause	Management
Anthracnose and Decline	Brown spots up to 1/4 inch with reddish-brown halos; spots may pepper leaves or follow veins. Large brown blotches on leaf tips, margins, or between veins. Branch tips blighted, leaves persist through winter. Reddish-brown spots on flower bracts. Lower twigs and branches die; pimple-like fruiting structures on dead twigs. Water sprouts on trunk of severely affected trees. Tree may die over several years.	Discula destructiva	Prune and destroy dead twigs/branches during dormancy and growing season. Protect from drought, winter injury, and dogwood borer. Rake and destroy fallen leaves. Apply fungicide at bud break. Plant resistant Kousa dogwood (C. kousa) or hybrids of kousa and native dogwood.
Leaf and Flower Blight	Irregular brown, wrinkled patches on flower bracts and leaves in spring. Gray mold develops under high humidity.	Botrytis cinerea	Occurs only in very wet, humid springs. Warm, dry weather curtails disease.
Crown Canker	Leaves smaller, light green, premature fall color. Twigs and large branches die as canker forms at base, slowly girdling tree. Tree flowers/fruits profusely but eventually dies.	Phytophthora cactorum	Remove infected tree; do not replace with woody ornamental until soil fumigated and aerated. Apply fungicide to protect plants.
Powdery Mildew	White fungal growth on leaf surfaces late summer and autumn.	Erysiphe pulchra and Phyllactinia guttata	Apply fungicide at first sign. Resistant species: Cornus kousa, C. sericea, C. mas, C. alternifolia, C. alba, C. controversa. Resistant C. florida cultivars: Jean's Appalachian Snow, Kay's Appalachian Mist, Karen's Appalachian Blush, Appalachian Joy.
Septoria Leaf Spot	Angular gray to brown spots with yellow or dark purple halos, up to 1/4 inch. Dark brown fruiting structures visible within spots.	Septoria cornicola	Apply fungicide to protect new leaves at bud break.
Spot Anthracnose	Reddish-purple spots on bracts up to 1/10 inch. Leaf spots circular to angular, dark purple, less than 1/32 inch, often dropping out (shot holes). Spots on twigs and fruit.	Elsinöe corni	See anthracnose management above.