Alderleaf Pepperbush Clethra alnifolia
Other Common Name(s):
Previously known as:
- Clethra tomentosa
- Phonetic Spelling
- KLETH-rah al-nih-FOH-lee-ah
- Description
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Clethra alnifolia, or 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 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.
Clethra tomentosa, a synonym for Clethra alnifolia, is native to the Southeastern United States (North Carolina, south to Florida, and west to Texas). It is similar to C. alnifolia except that it has foliage with soft, short hairs, and blossoms with very long racemes.
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.
- See this plant in the following landscape:
- Foundation Planting- West Side of House
- Cultivars / Varieties:
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'Crystalinia'
- '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'
Showy, fragrant flowers - 'Hummingbird'
- 'Crystalinia', 'Hummingbird', 'Paniculata', 'Pinkspire', 'Rosea', 'Ruby Spice', 'September Beauty', 'Sherry Sue', 'Sixteen Candles', 'White Doves'
- Tags:















- Cultivars / Varieties:
-
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'Crystalinia'
- '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'
Showy, fragrant flowers - 'Hummingbird'
- 'Crystalinia', 'Hummingbird', 'Paniculata', 'Pinkspire', 'Rosea', 'Ruby Spice', 'September Beauty', 'Sherry Sue', 'Sixteen Candles', 'White Doves'
- Tags:
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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.
- Dimensions:
- Height: 5 ft. 0 in. - 10 ft. 0 in.
- Width: 4 ft. 0 in. - 6 ft. 0 in.
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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
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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
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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.
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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.
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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.
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Bark:
- Bark Color:
- Dark Gray
- Surface/Attachment:
- Exfoliating
- Bark Description:
- Bark is grey and loosely striped
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Stem:
- Stem Color:
- Brown/Copper
- Red/Burgundy
- Stem Is Aromatic:
- No
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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