Summersweet Clethra
Common Name
Summersweet Clethra, Sweet Pepperbush
Family
Clethraceae
Tree or plant type / form
Deciduous shrub
Landscape Use
Effective in mass plantings, foundations, mixed borders or as a hedge; also useful in shade, woodland, or rain gardens.
Season of interest and/or other ornamental feature(s)
Provides exceptional four season interest with its lustrous green leaves in spring and summer, showy white or pink fragrant late summer flowers, golden yellow autumn leaves, and interesting, delicate dried seed capsules in winter.
Size at Landscape Maturity
Generally 4 to 8 feet tall and 3 to 4 feet wide in 10 years, but can vary by cultivar (see below). In favorable sites, the species can form large colonies via underground rhizomes.
Light exposure
Full sun to shade
USDA Hardiness zone
3 – 9
Origin / Native Locale
Native to the eastern United States, primarily near the Gulf and Atlantic Coasts.
Wildlife Value (incl. pollinators)
Highly attractive to a wide range of bees and other pollinators when in flower; songbirds feed on the seeds in fall and winter.
Soil Type & Drainage
Prefers moist, acidic soils but adaptable to a wide range of soil types including clay and sandy soils, as well as poorly drained conditions.
Tolerances
Tolerates shade, clay soils, wet conditions and road salt; rarely browsed by deer.
Leaf Description
The alternate, simple leaves are typically late to appear in spring. Measuring 2 to 4 inches long and 1 to 2 inches wide, they are often glossy on the upper surface.
Cone / Fruit
Dry, 3-valved 1/8 inch diameter capsule that turns brown in fall and persists for a year or more.
Flower Description
White flowers are extremely fragrant and densely arranged on cylindrical racemes up to 6 inches long. A pink-flowered selection, ‘Ruby Spice’ is very popular in the nursery trade.
Bloom Time in Northeast Ohio
Late July through August
Cultivars
‘Hummingbird’ is a well-known clone that has performed well at Secrest Arboretum but is represented by different forms in the nursery trade. The true form is that of a low, spreading, colonizing shrub growing only 3 to 4 feet tall but spreading much wider. Some plants sold as ‘Hummingbird’ instead exhibit a more erect growth habit. ‘Sixteen Candles’ is highly recommended for its compact size (4 to 5 feet tall), lustrous dark green foliage, and strongly vertical flower racemes. ‘Ruby Spice’ offers pink flowers on an upright, vigorous shrub reaching 6 to 8 feet tall.
Available at
Secrest Plant Sales and selected local nurseries
Use the Secrest Aboretum Explorer to find locations where this plant is located on the Wooster campus.
