Summersweet, Sweet Pepper Bush
Clethra alnifolia 'Hummingbird'

Family: Clethraceae
Genus: Clethra (KLEE-thra) (Info)
Species: alnifolia (al-nee-FOH-lee-uh) (Info)
Cultivar: Hummingbird




36-48 in. (90-120 cm)


36-48 in. (90-120 cm)


USDA Zone 3b: to -37.2 C (-35 F)

USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

USDA Zone 9a: to -6.6 C (20 F)

USDA Zone 9b: to -3.8 C (25 F)

Sun Exposure:

Full Sun

Sun to Partial Shade

Light Shade


Unknown - Tell us

Bloom Color:

White/Near White

Bloom Time:

Mid Summer

Late Summer/Early Fall




Other details:

This plant is attractive to bees, butterflies and/or birds

Flowers are fragrant

Requires consistently moist soil; do not let dry out between waterings

Soil pH requirements:

5.6 to 6.0 (acidic)

6.1 to 6.5 (mildly acidic)

Patent Information:

Unknown - Tell us

Propagation Methods:

Unknown - Tell us

Seed Collecting:

Unknown - Tell us


This plant has been said to grow in the following regions:

Lula, Georgia

Iowa City, Iowa

Northfield, Massachusetts

Redford, Michigan

Baldwinsville, New York

Davidson, North Carolina

Star, North Carolina

Cincinnati, Ohio

Dublin, Ohio

Mogadore, Ohio

Norristown, Pennsylvania

West Chester, Pennsylvania

Old Hickory, Tennessee

Rockwood, Tennessee

Linden, Virginia

South Boston, Virginia

Vancouver, Washington

Ellsworth, Wisconsin

show all

Gardeners' Notes:


On Mar 14, 2009, cedar18 from Lula, GA (Zone 7b) wrote:

I may regret putting this shrub in a perennial border since it suckers, but it has a nice form and I was sold on it after watching a hummingbird visit it. This plant did not do well for me in partial shade (poor soil, granted) but it has thrived in sun, adequate water and good soil.


On Aug 6, 2006, winging from Cincinnati, OH (Zone 6a) wrote:

Thrives in partial shade but as noted above, it can be late to leaf out. My mature plant is a bit sprawled, so I've supported it with a ring support. This improves the overall appearance of the plant. I otherwise pretty much leave this alone, except for random deadheading of the old bracts in the spring and summer by snapping them off when I happen to be near-by. White flowers lighten up shady areas.


On May 21, 2005, sanity101 from Dublin, OH (Zone 5b) wrote:

It's very late to leaf out in the spring. Every year we think it's dead, but around mid-May it finally sends its leaves out and looks fine. That coupled with a somewhat leggy structure makes it more of a 'backyard' plant than something for the front walk, but it smells so wonderful, and holds its flowers for a long time. Does attract bees though. (plants referenced are in part-shade)


On Apr 9, 2003, kategw wrote:

Wonderful fragrance, longlasting flowers, good yellow fall foliage, neat winter structure with seed pods lasting all winter.