Clethra / Summersweet
Lustrous leaves, fragrant flowers, fall color, winter seed spikes and colorful stems
The Clethra genus contains about 65 species of deciduous and evergreen flowering shrubs, commonly called summersweet or sweet-pepper bush. C. acuminata (cinnamon clethra) and C. barbinervis (Japanese clethra) are used in home gardens, but C. alnifolia (summersweet [C. tomentosa]) is the most popular today, with many cultivars available.
A native understory shrub, summersweet grows in eastern North America from southern Maine south to Florida and west to Texas, often found in sandy soils along seashores on the coast or in swampy woodlands, damp thickets, wet marshes, and along stream banks. This shade-tolerant, suckering, thicket-forming shrub grows slowly and reaches a mature height between 4 and 8 feet with a width of 4 to 6 feet. It has a rounded, densely branched habit with scaly, cinnamon-colored to dark gray or brown-black bark, which is an especially attractive feature in winter after the leaves drop.
Summersweet blooms heavily from mid to late summer in showy upright to drooping flower spikes filled with small white or pink flowers. Sweetly scented, the nectar- and pollen-rich flowers sustain bees and butterflies. In September to October, the foliage turns shades of yellow or gold when flowers give way to delicate dark brown seed capsules, which may persist into winter, unless consumed by hungry songbirds.
Summersweet performs beautifully as a specimen plant but is shown to best effect when grouped, and it makes a lovely shrub border. It’s perfect for naturalized areas around ponds and streams and for butterfly, native, shade, and woodland gardens.
Cold hardy and trouble free, summersweet grows best in locations with part shade and moist, well-draining soils. It tolerates full sun or full shade but will not tolerate dry soil for long periods. It is disease, pest, and deer resistant.