Swamp Dogwood (Cornus foemina) is a native deciduous shrub found across the eastern and southeastern United States. It tolerates — and actively performs best in — consistently wet soils, making it a practical choice for rain gardens, streambanks, pond margins, and low-lying areas where most shrubs fail. Flat-topped clusters of small white flowers appear in late spring, followed by pale blue-white drupes in late summer that are heavily used by migratory birds.
This shrub grows 6 to 15 feet tall with a multi-stemmed habit and spreads gradually by root suckers, which makes it effective for stabilizing wet slopes and stream edges. The stems turn reddish-purple in winter, providing seasonal interest after leaf drop. Full sun to partial shade produces the best fruit set; deep shade significantly reduces both flowering and fruiting. Established plants require minimal maintenance and tolerate periodic flooding and clay soils. It is cold-hardy to roughly -8°C when dormant.
The bark of Cornus foemina, like that of related dogwood species, was used by various Native American peoples as an astringent and as a substitute for quinine in treating intermittent fevers. This is attributed to iridoid glycosides present in the bark. These are traditional ethnobotanical uses, not clinical applications.
Dogwood Anthracnose
Irregular tan to brown spots on leaves with distinct purple or reddish margins, often starting at leaf tips and edges. In advanced cases: blighted shoots, stem cankers, and epicormic sprouts emerging from the lower trunk. Infected dead leaves may cling to branches through winter rather than dropping.
Remove and destroy all infected leaves, shoots, and cankered branches. Avoid overhead irrigation. Apply a copper-based or chlorothalonil fungicide starting at bud break in spring, repeating every 10–14 days during wet weather. Maintain tree vigor with consistent moisture and mulch — stressed trees are far more vulnerable. In high-pressure sites, consider replacing with anthracnose-resistant cultivars such as 'Appalachian Spring'.
Dogwood Canker
Sunken, discolored, or cracked areas on stems and branches; wood beneath the canker is brown and dead; affected stems wilt and die back from the canker site toward the tip.
Prune infected stems at least 6 inches below visible canker tissue. Sterilize cutting tools with 70% isopropyl alcohol between each cut. Dispose of removed material — do not compost. Maintain plant vigor through consistent watering and avoid wounding stems during routine maintenance. No chemical controls are reliably effective once infection is established; prevention through plant health is the primary strategy.
Powdery mildew
White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.
Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.
Cercospora Leaf Spot
Small round spots with tan or gray centers and reddish-purple borders on leaves. Spots merge in severe cases, causing leaves to brown and die back.
Remove infected leaves and avoid overhead watering. Space plants for airflow and rotate crops. Apply a copper-based fungicide if the infection spreads.