Clethra alnifolia (Summersweet)

Gloriously fragrant, Clethra alnifolia (Summersweet) is a slowly spreading, densely-branched, deciduous shrub boasting bottlebrush spikes of extremely fragrant white flowers in mid to late summer.

Gloriously fragrant, Clethra alnifolia (Summersweet) is a slowly spreading, densely-branched, deciduous shrub boasting bottlebrush spikes of extremely fragrant white flowers in mid to late summer. Lasting about for 4-6 weeks, the blossoms open from bottom to top. They are very attractive to bees, butterflies, and other pollinators, at a time of the year when there's not a wealth of nectars to choose from. The flowers give way to spikes of dark brown fruits which persist into winter, providing continuing interest. The serrated, glossy, dark green foliage turns rich golden yellow in fall. One of its most attractive characteristics is to produce great blooms in shady locations. This summer-flowering shrub spreads slowly by suckers forming large colonies. Free of any disease or pest problems, it is excellent for coastal gardens due to salt-spray tolerance, in shrub borders, or along streams and ponds. A dependable shrub that is native from coastal Maine south to north Florida and then west to the eastern edge of Texas.

  • Grows 3-8 feet tall (90-240 cm) with a spread of 4-6 ft. (120-180 cm).
  • This plant is best grown in full sun to part shade in average, medium to wet, acidic, sandy soils. Full shade is tolerated. Clay and wet soil tolerant.
  • Mass in mixed shrub borders for dramatic summer blooms. Great flowering shrub for shade or woodland gardens or along stream banks or ponds. May be naturalized in cottage gardens, wild gardens, or naturalized areas
  • No serious pest or disease issues. Flowers attract birds, butterflies, and hummingbirds. Clethra alnifolia is rarely bothered by deer.
  • This shrub flowers on new wood, so pruning for shape is best done in spring. Promptly remove root suckers unless naturalized look is desired
  • Propagate by cuttings.
  • Native to eastern North America.

Requirements

Hardiness 3
– 9

Heat Zones 1
– 9

Climate Zones 1, 1A, 1B, 2, 2A, 2B, 3, 3A, 3B, 4, 5, 6, A2, A3
Plant Type Shrubs
Plant Family Clethra
Exposure Full Sun, Partial Sun, Shade
Season of Interest Summer (Mid,Late)Fall
Height 3'
– 8'
(90cm
– 240cm)
Spread 4'
– 6'
(120cm
– 180cm)
Spacing 48″
– 72″
(120cm
– 180cm)
Water Needs Average
Maintenance Low
Soil Type Clay, Loam, Sand
Soil pH Acid
Soil Drainage Moist but Well-Drained
Characteristics Fragrant, Showy
Native Plants United States, Northeast, Connecticut, Delaware, Maine, Massachusetts, Maryland, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Southeast, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, Southwest, Texas
Tolerance Clay Soil, Deer, Salt, Wet Soil
Attracts Bees, Birds, Butterflies, Hummingbirds
Garden Uses Beds and Borders, Ponds and Streams, Rain Gardens
Garden Styles Coastal Garden, Informal and Cottage, Prairie and Meadow, Traditional Garden