Create Your Garden

Clethra alnifolia (Summersweet)

Coastal Pepperbush, Coastal Sweet Pepperbush, Coastal Sweet Pepper, Alderleaf Pepperbush, Alderleaf Clethra, Clethra, Summer Sweet, Clethra tomentosa

Clethra Alnifolia, Coastal Pepperbush, Coastal Sweet Pepperbush, Coastal Sweet Pepper, Alderleaf Pepperbush, Alderleaf Clethra, Clethra, Summer Sweet

Gloriously fragrant, Clethra alnifolia (Summersweet) is a slowly spreading, densely-branched, deciduous shrub boasting bottlebrush spikes of extremely fragrant white flowers in mid to late summer. Lasting about for 4-6 weeks, the blossoms open from bottom to top. They are very attractive to bees, butterflies, and other pollinators, at a time of the year when there’s not a wealth of nectars to choose from. The flowers give way to spikes of dark brown fruits, which persist into winter, providing continuing interest. The serrated, glossy, dark green foliage turns rich golden yellow in fall. One of its most attractive characteristics is to produce great blooms in shady locations. This summer-flowering shrub spreads slowly by suckers forming large colonies. Free of any disease or pest problems, it is excellent for coastal gardens due to salt-spray tolerance, in shrub borders, or along streams and ponds. A dependable shrub native from coastal Maine south to north Florida and then west to the eastern edge of Texas.

  • Grows 3-8 feet tall (90-240 cm) with a spread of 4-6 ft. (120-180 cm).
  • This plant is best grown in full sun to part shade in average, medium to wet, acidic, sandy soils. Full shade is tolerated. Clay and wet soil tolerant.
  • Mass in mixed shrub borders for dramatic summer blooms. Great flowering shrub for shade or woodland gardens or along stream banks or ponds. May be naturalized in cottage gardens, wild gardens, or naturalized areas.
  • No serious pest or disease issues. Flowers attract birds, butterflies, and hummingbirds. Clethra alnifolia is rarely bothered by deer.
  • This shrub flowers on new wood, so pruning for shape is best done in spring. Promptly remove root suckers unless a naturalized look is desired.
  • Propagate by cuttings.
  • Native to eastern North America.

Requirements

Hardiness 3 - 9
Heat Zones 1 - 9
Climate Zones 1, 1A, 1B, 2, 2A, 2B, 3, 3A, 3B, 4, 5, 6, A2, A3
Plant Type Shrubs
Plant Family Clethraceae
Genus Clethra
Common names Clethra
Exposure Full Sun, Partial Sun, Shade
Season of Interest Summer (Mid, Late)
Fall
Height 3' - 8'
(90cm - 240cm)
Spread 4' - 6'
(120cm - 180cm)
Spacing 48" - 72"
(120cm - 180cm)
Maintenance Low
Water Needs Average
Soil Type Clay, Loam, Sand
Soil pH Acid
Soil Drainage Moist but Well-Drained
Characteristics Fragrant, Showy
Native Plants United States, Massachusetts, New Jersey, New Hampshire, Maryland, Pennsylvania, Maine, Delaware, Connecticut, Rhode Island, New York, Southwest, Southeast, Northeast, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, Florida, Georgia, Texas
Tolerance Full Shade, Deer, Salt, Clay Soil, Wet Soil
Attracts Bees, Birds, Butterflies, Hummingbirds
Garden Uses Beds And Borders, Ponds And Streams, Rain Gardens
Garden Styles Coastal Garden, Informal and Cottage, Prairie and Meadow, Traditional Garden
How Many Plants
Do I Need?
Not sure which Clethra to pick?
Compare Now

Alternative Plants to Consider

Clethra acuminata (Cinnamon Clethra)
Clethra barbinervis (Japanese Clethra)
Clethra alnifolia ‘Caleb’ VANILLA SPICE’ (Summersweet)
Clethra alnifolia ‘Hummingbird’ (Summersweet)
Clethra alnifolia ‘Ruby Spice’ (Summersweet)

Recommended Companion Plants

Polygonatum odoratum ‘Variegatum’ (Solomon’s Seal)
Hakonechloa macra ‘Aureola’ (Hakone Grass)
Actaea simplex (Atropurpurea Group) ‘James Compton’ (Baneberry)
Astilbe ‘Bridal Veil’ (Arendsii Hybrid)
Magnolia virginiana (Sweet Bay Magnolia)
Lyonia lucida (Fetter Bush)
Acer rubrum (Red Maple)
Vaccinium corymbosum (Highbush Blueberry)
Cephalanthus occidentalis (Button Bush)
Hibiscus coccineus (Scarlet Rose Mallow)
Crinum americanum (Swamp Lily)
Iris hexagona (Dixie Iris)
While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.
Buy Plants

Requirements

Hardiness 3 - 9
Heat Zones 1 - 9
Climate Zones 1, 1A, 1B, 2, 2A, 2B, 3, 3A, 3B, 4, 5, 6, A2, A3
Plant Type Shrubs
Plant Family Clethraceae
Genus Clethra
Common names Clethra
Exposure Full Sun, Partial Sun, Shade
Season of Interest Summer (Mid, Late)
Fall
Height 3' - 8'
(90cm - 240cm)
Spread 4' - 6'
(120cm - 180cm)
Spacing 48" - 72"
(120cm - 180cm)
Maintenance Low
Water Needs Average
Soil Type Clay, Loam, Sand
Soil pH Acid
Soil Drainage Moist but Well-Drained
Characteristics Fragrant, Showy
Native Plants United States, Massachusetts, New Jersey, New Hampshire, Maryland, Pennsylvania, Maine, Delaware, Connecticut, Rhode Island, New York, Southwest, Southeast, Northeast, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, Florida, Georgia, Texas
Tolerance Full Shade, Deer, Salt, Clay Soil, Wet Soil
Attracts Bees, Birds, Butterflies, Hummingbirds
Garden Uses Beds And Borders, Ponds And Streams, Rain Gardens
Garden Styles Coastal Garden, Informal and Cottage, Prairie and Meadow, Traditional Garden
How Many Plants
Do I Need?
Not sure which Clethra to pick?
Compare Now

Gardening Ideas

Plant Calculator

How many Clethra alnifolia (Summersweet) do I need for my garden?

Input your garden space dimensions

Your Shopping List

Plant Quantity
Clethra alnifolia (Summersweet) N/A Buy Plants

Please Login to Proceed

You Have Reached The Free Limit, Please Subscribe to Proceed

Subscribe to Gardenia

To create additional collections, you must be a paid member of Gardenia
  • Add as many plants as you wish
  • Create and save up to 25 garden collections
Become a Member

Plant Added Successfully

You have Reached Your Limit

To add more plants, you must be a paid member of our site Become a Member

Update Your Credit
Card Information

Cancel

Create a New Collection

Sign Up to Our Newsletter

    You have been subscribed successfully

    Join Gardenia.net

    Create a membership account to save your garden designs and to view them on any device.

    Becoming a contributing member of Gardenia is easy and can be done in just a few minutes. If you provide us with your name, email address and the payment of a modest $25 annual membership fee, you will become a full member, enabling you to design and save up to 25 of your garden design ideas.

    Join now and start creating your dream garden!

    Join Gardenia.net

    Create a membership account to save your garden designs and to view them on any device.

    Becoming a contributing member of Gardenia is easy and can be done in just a few minutes. If you provide us with your name, email address and the payment of a modest $25 annual membership fee, you will become a full member, enabling you to design and save up to 25 of your garden design ideas.

    Join now and start creating your dream garden!

    Find your Hardiness Zone

    Find your Heat Zone

    Find your Climate Zone