Sweet Pepperbush Plant Care
Clethra alnifolia L.
Clethra alnifolia, the coastal sweetpepperbush or summer sweet, is a species of flowering plant in the genus Clethra of the family Clethraceae, native to eastern North America from southern Nova Scotia and Maine south to northern Florida, and west to eastern Texas. It is a deciduous shrub which grows in wetlands, bogs and woodland streams.
Every 3–7 days
Partial shade to full sun
50–80°F
40–70%
What Is the Sweet Pepperbush?
Sweet Pepperbush (Clethra alnifolia) belongs to the Clethraceae family within the Clethra genus. Sweet Pepperbush is native to eastern North America from southern Nova Scotia and Maine south to northern Florida, and west to eastern Texas. Sweet Pepperbush is also known as Coastal Pepperbush, Summersweet, White Alder.
Sweet Pepperbush displays an upright, spreading shrub growth habit, reaching up to 6 inches tall with a spread of approximately 8 inches. Sweet Pepperbush produces fragrant white or pink bottlebrush-like flowers.
Leaf size: approximately 4 inches.
How Often Should You Water a Sweet Pepperbush?
Clethra alnifolia requires watering every 3–7 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 3–7 days
Let soil partially dry between waterings
What Light Does the Sweet Pepperbush Need?
Sweet Pepperbush thrives in partial shade to full sun light conditions. The optimal light range is 500–2000 lux. Avoid placing Sweet Pepperbush in direct, harsh sunlight for extended periods, as this can scorch the foliage.
Light Requirement
Partial shade to full sun
500–2000 lux
What Temperature and Humidity Does the Sweet Pepperbush Prefer?
Clethra alnifolia grows best at temperatures between 50°F and 80°F. Sweet Pepperbush prefers humidity levels of 40–70%.
Temperature
50–80°F
Humidity
40–70%
What Soil Mix Works Best for a Sweet Pepperbush?
Moist, acidic, well-draining soil rich in organic matter. Good drainage is essential for Sweet Pepperbush to prevent waterlogging, which leads to root rot and fungal issues.
How Do You Repot a Sweet Pepperbush?
Repot every 2-3 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Sweet Pepperbush?
Sweet Pepperbush can be propagated through softwood cuttings, seeds.
Fertilizing
Every 6 months
During the growing season
Is the Sweet Pepperbush Toxic to Pets and Children?
Non-Toxic
Non-toxic to humans and pets
What Pests and Diseases Affect the Sweet Pepperbush?
Sweet Pepperbush is susceptible to aphids, scale insects, spider mites. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
What USDA Hardiness Zone Does the Sweet Pepperbush Need?
Sweet Pepperbush grows outdoors in USDA Zone 12a. Native to eastern North America from southern Nova Scotia and Maine south to northern Florida, and west to eastern Texas, Sweet Pepperbush is adapted to warm climates. In cooler regions, grow Sweet Pepperbush as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 12a
Keep exploring plants
Sweet Pepperbush is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Clethra genus — compare its care with other Clethra species on PlantoScan.
Sweet Pepperbush tolerates low-light rooms and shaded spots — browse the full list of low-light plants.
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