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Clethra alnifolia

Phonetic Spelling
KLETH-rah al-nih-FOH-lee-ah
Description

Sweet Pepperbush is a deciduous shrub that may grow to 5 to 10 feet. The leaves are alternate with a finely toothed margin. The bark is gray and loosely striped. Small, white flowers occurring in dense clusters on long 3- to 6-inch terminal spikes mature in late summer. The shrub produces a brown, dry capsule that matures in the fall.

‘Sixteen Candles’ and ‘Hummingbird’ are compact shrubs with white flowers.  ‘Rosea,’ ‘Pink Spires’ and ‘Ruby Spice’ are three pink-flowered cultivars.  ‘Ruby Spice’ is the darkest pink color, which holds even in the coastal plains.  ‘Sherry Sue’ sports white flowers and bright red stems.  ‘September Beauty’ is noteworthy for flowering later in the season. Another interesting species, Clethra tomentosa, has foliage that has soft, short hairs, and very long racemes.  The Japanese pepperbush, Clethra barbinervis, exhibits beautiful cinnamon-colored exfoliating bark as it matures.

Fire Risk: This plant has a low flammability rating.

Insects, Diseases, or Other Plant Problems:  Spider mites may be a concern in dry conditions.  When planted in the proper site, it is insect- and disease- resistant.

Quick ID Hints:

  • fragrant racemes of white flowers
  • blooms mid to late summer
  • persistent fruit capsules
  • Serrated leaves are usually entire toward base

Upright, deciduous shrub 5- 8' tall and 4- 6' wide. 

Blooms in July and August on current season growth. Late to leaf out in spring. Fall foliage is yellow-green to golden brown. Good as screen, specimen, in groupings or shrub border. Pest free except for spider mites. 

Prefers moist, acidic soil with organic material, full sun to partial shade, avoid hot, dry sites.

 

Cultivars / Varieties:
  • 'Crystalinia'
  • 'Hummingbird'
  • 'Paniculata'
  • 'Pinkspire'
  • 'Rosea'
  • 'Ruby Spice'
  • 'September Beauty'
  • 'Sherry Sue'
  • 'Sixteen Candles'
  • 'White Doves'
Tags:
#bees#hummingbirds#butterflies#showy flowers#deciduous#birds#white flowers#wildlife plant#native shrub#salt tolerant#playground#coastal#wet sites#pond margins#moist soil#food source#highly beneficial coastal plants#salt spray tolerant#cpp#low flammability#NC native#deer damage#deer resistant#children's garden#native garden#fire resistant#edible fruits#pollinator plant#fantz#hummingbird#food source fall#butterfly
 
Cultivars / Varieties:
  • 'Crystalinia'
  • 'Hummingbird'
  • 'Paniculata'
  • 'Pinkspire'
  • 'Rosea'
  • 'Ruby Spice'
  • 'September Beauty'
  • 'Sherry Sue'
  • 'Sixteen Candles'
  • 'White Doves'
Tags:
#bees#hummingbirds#butterflies#showy flowers#deciduous#birds#white flowers#wildlife plant#native shrub#salt tolerant#playground#coastal#wet sites#pond margins#moist soil#food source#highly beneficial coastal plants#salt spray tolerant#cpp#low flammability#NC native#deer damage#deer resistant#children's garden#native garden#fire resistant#edible fruits#pollinator plant#fantz#hummingbird#food source fall#butterfly
  • Attributes:
    Genus:
    Clethra
    Species:
    alnifolia
    Family:
    Clethraceae
    Life Cycle:
    Perennial
    Woody
    Country Or Region Of Origin:
    South East Canada to Texas
    Distribution:
    Maine to Florida
    Fire Risk Rating:
    low flammability
    Wildlife Value:
    Hummingbirds, butterflies and other pollinators are attracted to the blooms. Fruits are eaten by birds and small mammals.
    Play Value:
    Attracts Pollinators
    Edible fruit
    Wildlife Food Source
    Particularly Resistant To (Insects/Diseases/Other Problems):
    fire in the landscape.
    Dimensions:
    Height: 5 ft. 0 in. - 10 ft. 0 in.
    Width: 4 ft. 0 in. - 6 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Native Plant
    Shrub
    Leaf Characteristics:
    Deciduous
    Habit/Form:
    Erect
    Multi-stemmed
    Growth Rate:
    Medium
    Maintenance:
    Low
    Texture:
    Medium
  • Cultural Conditions:
    Light:
    Deep shade (Less than 2 hours to no direct sunlight)
    Full sun (6 or more hours of direct sunlight a day)
    Partial Shade (Direct sunlight only part of the day, 2-6 hours)
    Soil Texture:
    Clay
    High Organic Matter
    Loam (Silt)
    Sand
    Soil pH:
    Acid (<6.0)
    Neutral (6.0-8.0)
    Soil Drainage:
    Good Drainage
    Moist
    Occasionally Wet
    NC Region:
    Coastal
    Piedmont
    Usda Plant Hardiness Zone:
    3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b
  • Fruit:
    Fruit Color:
    Brown/Copper
    Display/Harvest Time:
    Fall
    Fruit Type:
    Capsule
    Fruit Description:
    Brown capsules which persist through winter. Dry, 3-valved, dehiscent, pubescent, 1/8" diameter capsule that turns brown in fall and persists for a year or more.
  • Flowers:
    Flower Color:
    Pink
    White
    Flower Inflorescence:
    Raceme
    Spike
    Flower Value To Gardener:
    Fragrant
    Flower Bloom Time:
    Summer
    Flower Shape:
    Cup
    Flower Size:
    3-6 inches
    Flower Description:
    Fragrant white flowers appear as dense, narrow, cylindric spikes, 2-6 inches long, which are often clustered together at branch ends. Blooms on new growth. Racemes - 3-5" long, showy. Numerous, fragrant, small white flowers.
  • Leaves:
    Leaf Characteristics:
    Deciduous
    Leaf Color:
    Brown/Copper
    Gold/Yellow
    Green
    Leaf Feel:
    Glossy
    Deciduous Leaf Fall Color:
    Brown/Copper
    Gold/Yellow
    Leaf Type:
    Simple
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Oblong
    Obovate
    Leaf Margin:
    Serrate
    Hairs Present:
    No
    Leaf Length:
    3-6 inches
    Leaf Description:
    Glossy in summer, medium to dark green leaves (to 3-4” long) turn variable but generally attractive shades of yellow to golden brown in fall (some do not have fall color though). The leaves are late to leaf out in spring. Alternate, simple leaves 1.5- 4" long and 1- 2" wide, obovate with acute to acuminate tip, serrated margins, lustrous medium to dark green.
  • Bark:
    Bark Color:
    Dark Gray
    Bark Description:
    Bark is grey and loosely striped
  • Stem:
    Stem Color:
    Brown/Copper
    Red/Burgundy
    Stem Is Aromatic:
    No
  • Landscape:
    Landscape Location:
    Coastal
    Naturalized Area
    Patio
    Pond
    Recreational Play Area
    Woodland
    Landscape Theme:
    Children's Garden
    Cottage Garden
    Edible Garden
    Native Garden
    Pollinator Garden
    Rain Garden
    Design Feature:
    Border
    Foundation Planting
    Small groups
    Attracts:
    Butterflies
    Hummingbirds
    Pollinators
    Small Mammals
    Songbirds
    Resistance To Challenges:
    Deer
    Fire
    Salt
    Wet Soil