Content Detail

A wide variety of butterflies and songbirds are attracted to summersweet clethra for its nectar and seeds. Native to the eastern United States, it provides exceptional four season interest with its lustrous green leaves in the spring, spiky white or pink fragrant summer flowers, golden yellow autumn leaves, and interesting, delicate dried seed capsules in winter.

  • Family (English) Summersweet
  • Family (botanic) Clethraceae
  • Tree or plant type Shrub
  • Native locale North America
  • Size range Small shrub (3-5 feet), Medium shrub (5-8 feet)
  • Light exposure Full sun (6 hrs direct light daily), Partial sun / shade (4-6 hrs light daily), Full shade (4 hrs or less of light daily)
  • Hardiness zones Zone 4, Zone 5 (Chicago), Zone 6, Zone 7, Zone 8, Zone 9
  • Soil preference Acid soil, Moist, well-drained soil, Wet soil
  • Tolerances Alkaline soil, Occasional flooding, Road salt, Wet sites
  • Season of interest early winter, midwinter, midsummer, late summer, early fall, mid fall, late fall
  • Flower color and fragrance Fragrant, Pink, White
  • Shape or form Oval, Round, Thicket-forming, Upright
  • Growth rate Moderate, Slow

Size and form:

This shrub can grow from three to eight feet with an oval, upright shape. It is thicket-forming.

Native geographic location and habitat:

It is a native to the eastern coast of the United States.

Attracts birds, pollinators and mammals:

Songbirds, including robin, goldfinch, and warblers are attracted to the seed capsules. It is a nectar source for swallowtail butterflies and hummingbirds.

Bark color and texture:

The multi-stemmed bark is brown.

Leaf or needle arrangement, size, shape, and texture:

The two to four inch simple, alternate sharply serrated leaves are medium to dark green above, paler beneath. It is slow to leaf out in spring. The leaves turn a golden-yellow in fall.

Flower description:

The fragrant, five-petaled flowers are in upright spikes on the end of branches. Color varies by cultivar from white to pink.

Fruit, cone, nut, and seed descriptions:

An interesting, delicate, dried seed capsules persist through winter.

Plant care:

This shrub grows best in part shade to full sun in moist to wet soils. It spreads by suckering roots forming wide colonies. Since it flowers on new wood, it can be pruned to control size in spring.

List of pests, diseases and tolerances:

There aren’t any serious problems. It is tolerant of different soil pH and aerial salt spray.

Hummingbird  (Clethra alnifolia ‘Hummingbird’):

A two to three feet high and wide rounded cultivar with white flower clusters that are larger and open earlier than the species.

Ruby Spice  (Clethra alnifolia ‘Ruby Spice’):

A four to six feet high and wide cultivar with an oval to rounded form and rosy pink flowers.

Sixteen Candles (Clethra alnifolia ‘Sixteen Candles’):

This cultivar is two to three feet high and wide rounded with white flowers.

Vanilla Spice™  (Clethra alnifolia ‘Caleb’):

A four to six feet high and three to five feet wide upright to rounded form cultivar with white flowers that are larger than those of the species.

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