# Sweet Pepperbush (Clethra alnifolia)

> Spires of intensely fragrant white flowers in August, when almost nothing else is blooming, and bees know it.

Also called summersweet, clethra, coastal sweetpepperbush. Category: Native Shrubs. Grown from seed by Blue Whale Trees. Web version: https://bluewhaletrees.com/plants/sweet-pepperbush/

![Sweet pepperbush (Clethra alnifolia) shoots in October sun, sharply toothed leaves crowded at their tips, water behind](https://bluewhaletrees.com/img/plants/sweet-pepperbush-2-h1610-800.jpg)
*Photo: Blue Whale Trees*

## Facts

- Type: Shrub
- Mature height: 4 to 8 ft
- USDA hardiness zones: 3 to 9
- Grows wild in: Stream banks, the coast, swamps and wet flats
- Native range: 20 states, north to [Maine](https://bluewhaletrees.com/tools/native/index.html.md?state=ME), south to [Florida](https://bluewhaletrees.com/tools/native/index.html.md?state=FL) and west to [Texas](https://bluewhaletrees.com/tools/native/index.html.md?state=TX) ([Alabama](https://bluewhaletrees.com/tools/native/index.html.md?state=AL), [Connecticut](https://bluewhaletrees.com/tools/native/index.html.md?state=CT), [Delaware](https://bluewhaletrees.com/tools/native/index.html.md?state=DE), [Florida](https://bluewhaletrees.com/tools/native/index.html.md?state=FL), [Georgia](https://bluewhaletrees.com/tools/native/index.html.md?state=GA), [Louisiana](https://bluewhaletrees.com/tools/native/index.html.md?state=LA), [Maine](https://bluewhaletrees.com/tools/native/index.html.md?state=ME), [Maryland](https://bluewhaletrees.com/tools/native/index.html.md?state=MD), [Massachusetts](https://bluewhaletrees.com/tools/native/index.html.md?state=MA), [Mississippi](https://bluewhaletrees.com/tools/native/index.html.md?state=MS), [New Hampshire](https://bluewhaletrees.com/tools/native/index.html.md?state=NH), [New Jersey](https://bluewhaletrees.com/tools/native/index.html.md?state=NJ), [New York](https://bluewhaletrees.com/tools/native/index.html.md?state=NY), [North Carolina](https://bluewhaletrees.com/tools/native/index.html.md?state=NC), [Pennsylvania](https://bluewhaletrees.com/tools/native/index.html.md?state=PA), [Rhode Island](https://bluewhaletrees.com/tools/native/index.html.md?state=RI), [South Carolina](https://bluewhaletrees.com/tools/native/index.html.md?state=SC), [Tennessee](https://bluewhaletrees.com/tools/native/index.html.md?state=TN), [Texas](https://bluewhaletrees.com/tools/native/index.html.md?state=TX) and [Virginia](https://bluewhaletrees.com/tools/native/index.html.md?state=VA))
- Sun: Full, Part, Shade
- Soil moisture: Average, Wet
- Growth rate: Medium
- Flowers: July to August
- Fruit: Capsules, September to February
- First crop: About 2 years
- Mature spread: 6 ft
- Traits: Showy flowers, Honey tree, Tolerates wet soil, Tolerates shade, Fall color, Winter interest, Erosion control, Salt tolerant
- Sold as: Saplings, Seed

Heights and zones are typical ranges for the species in cultivation; local conditions and seed source shift them.

## Availability

Saplings ship [bare-root](https://bluewhaletrees.com/articles/planting-bare-root-trees-on-arrival/index.html.md) or [in a pot](https://bluewhaletrees.com/articles/a-sapling-in-a-pot/index.html.md), [usually 12 to 18 inches tall](https://bluewhaletrees.com/articles/small-sapling-or-big-transplant/index.html.md), in the dormant season, and their [height and age](https://bluewhaletrees.com/articles/reading-a-nursery-listing/index.html.md) are stated with the price, once available. Live plants ship February to May and October to November. Not priced yet: leave an email on the web page for one email when it is priced, with a code for 10% off the plants in that order, not shipping or tax, or write to captain@bluewhaletrees.com.

## Notes

Summersweet grows in wet coastal woods from Maine to Texas and tolerates shade, salt spray and standing water. Its late-summer bloom is a lifeline for bees and butterflies and a notable honey plant. Suckers slowly into a colony; yellow fall color. One of the easiest native shrubs. Along a stream or pond its suckering roots form a low thicket that helps hold the bank. Belongs beside a porch or a back door, where the August scent drifts inside.

## Size, growth and what to expect

Few native shrubs bloom as late as sweet pepperbush, whose fragrant white spikes 3 to 6 inches long open on the current season's growth from July into August. It grows at a medium pace, roughly a foot and a half a year in its youth on an average site, which is the rate our growth estimator uses for it. It makes a dense, upright, multi-stemmed shrub 4 to 8 feet tall and 4 to 6 feet wide that suckers into a mounded clump.

The flowers carry high-quality nectar and pollen for bees, butterflies and hummingbirds. Dry brown capsules an eighth of an inch across ripen in September and October and hang on through winter. Birds pick out the seed. Summersweet, its other name, refers to that late, sweet-scented bloom.

It grows wild along the coast from Maine to Florida and west to Texas, in swampy woods, wet marshes and damp thickets, along streams and behind the shore, often on sand.

## How to grow Sweet Pepperbush

Sweet pepperbush is easy to place: full sun to fairly deep shade, ordinary garden soil or ground that stays wet, salt spray near the coast. It blooms most in sun. Plants slowly widen by suckers, so set them 4 feet apart and that far from a foundation.

Plant dormant bare-root or potted shrubs between leaf fall and bud break, in a wide, shallow hole. Set the crown at the soil line, put the native soil back in, and mulch out past the roots but not against the stems. It needs neither stake nor fertilizer. Seed is dust fine and needs no chilling. Scatter it on the surface of damp sand or seed mix in spring and press it in without covering it. Keep it constantly moist.

Water weekly through the first two summers; it wilts fast in dry soil until the roots are down. Deer browse it lightly and rabbits sometimes cut stems, so cage it low for a winter or two. It flowers on new wood, so prune in late winter, cutting the oldest stems to the ground to keep the clump full.

A lone sweet pepperbush sets some seed with its own pollen, but cross-pollinated flowers set more, so plant two or more seedlings if you want seed. Summersweet leafs out late, often not until late May, so do not write it off as dead. Spider mites trouble it in a hot, dry corner, one more reason to keep it moist. Flowers open in late July or August; leaves turn yellow in fall.

## Sources

- [NC State Extension Gardener Plant Toolbox: Clethra alnifolia](https://plants.ces.ncsu.edu/plants/clethra-alnifolia/)
- [Missouri Botanical Garden Plant Finder: Clethra alnifolia](https://plantfinder.mobot.org/PlantFinderDetails.aspx?kempercode=c230)
- [Lady Bird Johnson Wildflower Center: Clethra alnifolia](https://www.wildflower.org/plants/result.php?id_plant=CLAL3)
- [USDA Fire Effects Information System: Clethra alnifolia](https://www.fs.usda.gov/database/feis/plants/shrub/clealn/all.html)
- [USDA Forest Service, Woody Plant Seed Manual (2008), Clethra chapter, Griffin and Blazich](https://www.fs.usda.gov/nsl/Wpsm/Clethra.pdf)
- [USDA NRCS Plant Guide: coastal sweet pepperbush, Clethra alnifolia](https://plants.sc.egov.usda.gov/DocumentLibrary/plantguide/pdf/pg_clal3.pdf)
- [NatureServe Explorer: Clethra alnifolia, Coastal Sweet-pepperbush](https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.869567/Clethra_alnifolia)
- [Go Botany, Native Plant Trust: Clethra alnifolia](https://gobotany.nativeplanttrust.org/species/clethra/alnifolia/)
- [Trees and Shrubs Online: Clethra alnifolia, from Bean's Trees and Shrubs Hardy in the British Isles](https://www.treesandshrubsonline.org/articles/clethra/clethra-alnifolia/)
- [USDA NRCS PLANTS Database: Clethra alnifolia](https://plants.sc.egov.usda.gov/plant-profile/CLAL3)
- [The Morton Arboretum: summersweet clethra](https://mortonarb.org/plant-and-protect/trees-and-plants/summersweet-clethra/)
- [Flora of North America, vol. 8: Clethra alnifolia](http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=220003027)
- [Reed 2006, Reproductive biology of Clethra alnifolia, HortScience 41: 567-570, USDA Agricultural Research Service](https://www.ars.usda.gov/research/publications/publication/?seqNo115=188222)
- [Reed and Pooler 2012, 'Firefly' Clethra, HortScience 47(3): 429-430, USDA Agricultural Research Service](https://doi.org/10.21273/HORTSCI.47.3.429)
- [Reed, Joung and Roh 2002, Interspecific Hybridization in Clethra, HortScience 37(2): 393-397, USDA Agricultural Research Service](https://doi.org/10.21273/HORTSCI.37.2.393)

## Read before planting

- [Ten planting mistakes that quietly kill trees](https://bluewhaletrees.com/articles/ten-planting-mistakes/index.html.md)
- [Transplanting young trees: timing, water and protection](https://bluewhaletrees.com/articles/transplanting-young-trees/index.html.md)
- [Protecting young trees from voles, rabbits, deer and squirrels](https://bluewhaletrees.com/articles/protecting-trees-from-animals/index.html.md)
- [Native trees and shrubs for bees: pollen, nectar, nesting and a bloom calendar from willow to witch hazel](https://bluewhaletrees.com/articles/native-trees-for-bees/index.html.md)
- [Native trees and shrubs for butterflies and moths: host plants first, nectar second](https://bluewhaletrees.com/articles/native-trees-for-butterflies-and-moths/index.html.md)
- [The habitat around a tree is part of the tree](https://bluewhaletrees.com/articles/habitat-around-a-tree/index.html.md)

## Related

- Other clethras (Clethra) we grow: [Cinnamon Clethra](https://bluewhaletrees.com/plants/cinnamon-clethra/index.html.md)
- Plants that share its sun and soil: [Swamp Doghobble](https://bluewhaletrees.com/plants/swamp-doghobble/index.html.md), [Possumhaw Viburnum](https://bluewhaletrees.com/plants/possumhaw-viburnum/index.html.md), [Swamp Azalea](https://bluewhaletrees.com/plants/swamp-azalea/index.html.md) and [Maleberry](https://bluewhaletrees.com/plants/maleberry/index.html.md)
- Trees to plant it under: [Redbay](https://bluewhaletrees.com/plants/redbay/index.html.md), [Atlantic White Cedar](https://bluewhaletrees.com/plants/atlantic-white-cedar/index.html.md) and [Pond Cypress](https://bluewhaletrees.com/plants/pond-cypress/index.html.md)
- Same size, similar character: [Cinnamon Clethra](https://bluewhaletrees.com/plants/cinnamon-clethra/index.html.md), [American Fly Honeysuckle](https://bluewhaletrees.com/plants/american-fly-honeysuckle/index.html.md), [Carolina Buckthorn](https://bluewhaletrees.com/plants/carolina-buckthorn/index.html.md) and [Pinkshell Azalea](https://bluewhaletrees.com/plants/pinkshell-azalea/index.html.md)
- [Planting-site check](https://bluewhaletrees.com/tools/site-check/index.html.md): for a thrive, struggle or fail verdict on Sweet Pepperbush (Summersweet), add ?species=sweet-pepperbush with zone (2 to 10), sun (full, part, shade) and moisture (dry, average, wet) to that address; for example, the verdict for zone 3, part sun and average soil as Markdown is at https://bluewhaletrees.com/tools/site-check/index.html.md?species=sweet-pepperbush&zone=3&sun=part&moisture=average
- [Companion species for Sweet Pepperbush (Summersweet)](https://bluewhaletrees.com/tools/companions/index.html.md?species=sweet-pepperbush): the natives that share its ground and the plants that pair with it in a yard.
- [Tree growth estimator](https://bluewhaletrees.com/tools/growth/index.html.md): how the height and trunk projections are made; the estimate for Sweet Pepperbush (Summersweet) as Markdown is at https://bluewhaletrees.com/tools/growth/index.html.md?species=sweet-pepperbush (add height=, years= and site= poor, average or good)
- [Seed sowing planner](https://bluewhaletrees.com/tools/sowing/index.html.md): how Sweet Pepperbush (Summersweet) is sown, in the chart for every species (treatment, cold days, depth, timing); the dated plan for it as Markdown is at https://bluewhaletrees.com/tools/sowing/index.html.md?species=sweet-pepperbush (add state= and zone= for your own frost dates, method=fridge for the refrigerator route)
- [Pollination planner](https://bluewhaletrees.com/tools/pollination/index.html.md): what Sweet Pepperbush (Summersweet) needs for a crop and how many to plant, in the table for every species; the verdict for 2 of them as Markdown is at https://bluewhaletrees.com/tools/pollination/index.html.md?plants=sweet-pepperbush:2
- [Planting-window tool](https://bluewhaletrees.com/tools/planting-window/index.html.md): when to plant Sweet Pepperbush (Summersweet) where you live, as a fall and a spring window from the local frost dates; the windows as Markdown are at https://bluewhaletrees.com/tools/planting-window/index.html.md?species=sweet-pepperbush&state=MO&zone=6 with your own state and zone in place of those
- [Planting-distance tool](https://bluewhaletrees.com/tools/distance/index.html.md): how far Sweet Pepperbush (Summersweet) goes from a house, a septic field, a walk, wires, a property line and the next tree; the distances as Markdown are at https://bluewhaletrees.com/tools/distance/index.html.md?species=sweet-pepperbush&near=house,septic,pavement,wires,boundary,tree
- [Bloom and fruit calendar](https://bluewhaletrees.com/tools/calendar/index.html.md): the months Sweet Pepperbush (Summersweet) flowers and fruits, in the grid for every species; its own row and the gaps of a planting with it as Markdown at https://bluewhaletrees.com/tools/calendar/index.html.md?plants=sweet-pepperbush