Cornus alternifolia aka Alternate Leaf Dogwood

Cornus alternifolia, or pagoda dogwood, belongs to the dogwood family. It grows as a small tree or large, multi-stemmed shrub. Its native range spans central and eastern Canada and the United States. It grows in woods, along streams, and at forest edges. Garden plants reach 15–25 feet (4.6–7.6 metres) tall. They spread 20–32 feet (6.1–9.8 metres) wide. Some plants reach 30 feet (9.1 metres) in height. The branches form broad tiers, with tips that curve upward. This shape gives the plant its common name.

The plant grows slowly and sheds its leaves each year. Young bark is smooth and greenish-brown to reddish-brown. Older bark turns gray and develops shallow grooves. Slender stems range from green to reddish-purple. The simple, oval leaves grow in an alternate pattern. They crowd near branch tips and can look whorled. Their upper sides are dark green and smooth. Pale undersides bear fine hairs, and the veins are pinnate. Fall leaves turn red or purple, sometimes mixed with yellow.

Small, fragrant flowers open in May and June, after leaf growth. The cream to yellow-white blooms form flat clusters called cymes. These are modest blooms rather than large, bold flowers. Fruits turn from green through white to blue-black. These small drupes ripen from midsummer into late summer. Each holds a large seed on a red-orange stalk. Birds soon take the fruit, leaving the bright stalks behind. The fruit also feeds squirrels and other small mammals. Its sour, bitter flesh is not edible for people. Plants For A Future lists no known hazards.

Cool summers suit this dogwood best. Give it moist, rich soil that drains well. Acid soil is preferred, though RHS also lists neutral soil. Partial shade suits it, and cooler sites can support full sun. Hot sites call for shade during the afternoon. Keep the roots cool with mulch and supply steady moisture. Its shallow, spreading roots make transplanting hard. Sources list USDA zones 3–7 and UK hardiness H4. Use it as a specimen, in borders, or in woodland gardens. It offers birds nesting sites and draws butterflies and other pollinators.

Twig blight and canker can cause trouble in some places. Leaf spots, root rot, anthracnose, and honey fungus may occur. Scale insects, borers, and leaf miners can also attack. Wind and ice can break branches, and salt causes problems. Some plants have a short life. The bark has a history of medicinal use. Roots yield a brown dye, and the wood serves small turning projects.