Clethra acuminata

Common Names

Cinnamon Clethra, Mountain Sweet Pepperbush, Mountain Pepperbush

Summary

Clethra acuminata is a native eastern North American shrub or small tree, reaching up to about 20 feet tall with a 4–6 foot spread, often growing as an understory form in woodlands. It features cinnamon-colored, exfoliating bark, glossy green leaves that turn yellow in fall, and drooping racemes of white, fragrant flowers in summer that are rich in nectar and attract pollinators such as bees, butterflies, and hummingbirds.

Preferring moist, well-drained, humus-rich, acidic soils, it tolerates full sun to part shade with more bloom in partial sun and can adapt to drier sites; hardy in USDA zones 6a–7b. It is generally trouble-free, deer-resistant, and can form colonies slowly via suckering; propagation is possible by seed or softwood cuttings. Uses include woodland understory plantings, specimen plantings, shrub borders, and wildlife-friendly landscapes, with nectar-rich flowers enhancing pollinator gardens.

Lifecycle

Perennial

Height

8-20 feet

Spread

4-6 feet

Hardiness Zones

Zones 5-8

Sunlight Requirements

Ideally full Sun to Partial Shade; Full Shade is tolerated, but flowering is best with more sun.

Soil Type

Moist, well-drained, humus-rich, acidic soil (pH below 6), with textures of clay, loam, or sand, and rocky soil also favorable

Soil Drainage

Moist, well-drained soil.

Soil pH

pH less than 6.0

Bloom Color

White

Bloom Time

Summer (mid-to-late summer, roughly July to August)

Foliage Color

Green (dark green in summer; turns yellow and orange in fall)

Fall Foliage Color

Yellow to golden-yellow

Leaf Lifecycle

Deciduous, Evergreen broadleaf

Growth Rate

Slow

Seasons of Interest

Summer, Fall

Propagation Methods

Seeds and cuttings (including softwood cuttings), root cuttings

Attracts Wildlife

Attracts bees, hummingbirds, butterflies, other pollinators, and birds