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Alderleaf Pepperbush Clethra alnifolia

Previously known as:

  • Clethra tomentosa
Phonetic Spelling
KLETH-rah al-nih-FOH-lee-ah
Description

Sweet pepperbush, is a deciduous shrub that may grow to 5 to 10 feet. and often spreads into mounded clumps. It is native to eastern North America from Maine south to Florida and west to Texas. In the wild, it is often found in swamps, damp thickets, and sandy woods.

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 flowers produce high quality nectar and pollen that supports hummingbirds, butterflies, bees and other pollinators. The shrub produces a brown, dry capsule that matures in the fall. Sweet Pepperbush are unique among flowering shrubs because they bloom in shady locations in late summer when few other shrubs are in bloom.

This shrub is often grown as a screen, or as a specimen, on in groupings as a border. It prefers moist, sometimes wet, acidic soil with organic material, full sun to partial shade, but will not tolerate a hot, dry site. Dormant plants are hardy to about 22 degrees F (-30° C.). It is a good bee plant and the flowers are very aromatic. When grown in conditions similar to its native habitat, it will produce suckers and eventually form thickets. However, it responds well to pruning.

 

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

See this plant in the following landscape:
Foundation Planting- West Side of House
Cultivars / Varieties:
    'Crystalinia' Clethra alnifolia 'Crystalina'
    Showy, fragrant flowers
  • 'Hummingbird'
    Compact with white flowers.
  • 'Paniculata'
  • 'Pinkspire'
    Pink flowers.
  • 'Rosea'
    Pink flowers.
  • 'Ruby Spice'
    Darkest of the pink flowered cultivars, holds its color even in coastal sites.
  • 'September Beauty'
    Flowers late in the season.
  • 'Sherry Sue'
    White flowers and bright red stems.
  • 'Sixteen Candles'
    Compact with white flowers.
  • 'White Doves'
'Crystalinia', 'Hummingbird', 'Paniculata', 'Pinkspire', 'Rosea', 'Ruby Spice', 'September Beauty', 'Sherry Sue', 'Sixteen Candles', 'White Doves'
Tags:
#hummingbirds#showy flowers#deciduous#white flowers#wildlife plant#native shrub#salt tolerant#pond margins#specialized bees#moist soil#food source wildlife#highly beneficial coastal plants#salt spray tolerant#cpp#fire low flammability#NC native#summer flowers#deer browsing plant#deer resistant#children's garden#native garden#playground plant#edible fruits#pollinator plant#fantz#food source fall#NC Native Pollinator Plant#food source herbage#food source nectar#food source pollen#Piedmont Mountains FAC#Coastal FACW#wet soils tolerant#bird friendly#food source hard mast fruit#butterfly friendly#nectar plant early summer#nectar plant mid-summer#pollinator garden#bee friendly#Audubon#coastal plant
 
Cultivars / Varieties:
    'Crystalinia' Clethra alnifolia 'Crystalina'
    Showy, fragrant flowers
  • 'Hummingbird'
    Compact with white flowers.
  • 'Paniculata'
  • 'Pinkspire'
    Pink flowers.
  • 'Rosea'
    Pink flowers.
  • 'Ruby Spice'
    Darkest of the pink flowered cultivars, holds its color even in coastal sites.
  • 'September Beauty'
    Flowers late in the season.
  • 'Sherry Sue'
    White flowers and bright red stems.
  • 'Sixteen Candles'
    Compact with white flowers.
  • 'White Doves'
'Crystalinia', 'Hummingbird', 'Paniculata', 'Pinkspire', 'Rosea', 'Ruby Spice', 'September Beauty', 'Sherry Sue', 'Sixteen Candles', 'White Doves'
Tags:
#hummingbirds#showy flowers#deciduous#white flowers#wildlife plant#native shrub#salt tolerant#pond margins#specialized bees#moist soil#food source wildlife#highly beneficial coastal plants#salt spray tolerant#cpp#fire low flammability#NC native#summer flowers#deer browsing plant#deer resistant#children's garden#native garden#playground plant#edible fruits#pollinator plant#fantz#food source fall#NC Native Pollinator Plant#food source herbage#food source nectar#food source pollen#Piedmont Mountains FAC#Coastal FACW#wet soils tolerant#bird friendly#food source hard mast fruit#butterfly friendly#nectar plant early summer#nectar plant mid-summer#pollinator garden#bee friendly#Audubon#coastal plant
  • Attributes:
    Genus:
    Clethra
    Species:
    alnifolia
    Family:
    Clethraceae
    Life Cycle:
    Perennial
    Woody
    Recommended Propagation Strategy:
    Division
    Seed
    Stem Cutting
    Country Or Region Of Origin:
    Eastern North America
    Distribution:
    Maine to Florida and west to Texas.
    Fire Risk Rating:
    low flammability
    Wildlife Value:
    Hummingbirds, butterflies, native bees, and other pollinators are attracted to the nectar 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):
    Rebounds from fire in the landscape. Soil compaction tolerant. Resistant to Phytophthora root rot
    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
    Woody Plant Leaf Characteristics:
    Deciduous
    Habit/Form:
    Dense
    Erect
    Mounding
    Multi-stemmed
    Oval
    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
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    3a, 3b, 4a, 4b, 5b, 5a, 6a, 6b, 7a, 7b, 8a, 8b, 9b, 9a
  • Fruit:
    Fruit Color:
    Brown/Copper
    Display/Harvest Time:
    Fall
    Fruit Type:
    Capsule
    Fruit Width:
    < 1 inch
    Fruit Description:
    Brown capsules which ripen in the fall and persist through winter. Dry, 3-valved, dehiscent, pubescent, 1/8 inch diameter capsule that turns brown in fall and persists for a year or more. Fruit displays from September to October.
  • Flowers:
    Flower Color:
    Pink
    White
    Flower Inflorescence:
    Raceme
    Flower Value To Gardener:
    Fragrant
    Showy
    Flower Bloom Time:
    Summer
    Flower Shape:
    Cup
    Flower Size:
    3-6 inches
    Flower Description:
    Fragrant white flowers appear as dense, narrow, cylindric spikes, 2 to 6 inches long, which are often clustered together at branch ends. Blooms on current season growth. Racemes - 3 to 5 inches long, showy. Numerous, fragrant, small white flowers. They bloom from June to July.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Deciduous
    Leaf Color:
    Brown/Copper
    Gold/Yellow
    Green
    Leaf Feel:
    Glossy
    Leaf Value To Gardener:
    Showy
    Deciduous Leaf Fall Color:
    Brown/Copper
    Gold/Yellow
    Leaf Type:
    Simple
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Oblong
    Obovate
    Leaf Margin:
    Entire
    Serrate
    Hairs Present:
    No
    Leaf Length:
    3-6 inches
    Leaf Width:
    1-3 inches
    Leaf Description:
    Glossy in summer, medium to dark green leaves (to 3 to 4 inches 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 to 2 inches wide, obovate with acute to acuminate tip, serrated margins, entire toward the base, and lustrous medium to dark green.
  • Bark:
    Bark Color:
    Dark Gray
    Surface/Attachment:
    Exfoliating
    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
    Native Garden
    Pollinator Garden
    Rain Garden
    Design Feature:
    Border
    Foundation Planting
    Small groups
    Attracts:
    Bees
    Butterflies
    Hummingbirds
    Pollinators
    Small Mammals
    Songbirds
    Specialized Bees
    Resistance To Challenges:
    Deer
    Erosion
    Fire
    Heavy Shade
    Salt