Clethra alnifolia 'Ruby Spice'
Overview
Uses: Foundation plantings, shrub borders, shade gardens, rain gardens, woodland edges, mass plantings.
Benefits: Deep rose-pink bottlebrush flower spikes bloom in mid to late summer when few other shrubs are flowering. Intensely sweet, spicy fragrance carries through the garden and attracts butterflies, bees, and hummingbirds. Thrives in moist, shaded conditions where many flowering shrubs struggle.
USDA Hardiness Zones: 4–9
Sun: Full Sun to Full Shade
Life Cycle: Deciduous Shrub
Growth Habit: Upright, Rounded — densely branched with a compact oval form.
Bloom Color: Pink
Foliage Color: Green, turning golden yellow in fall
Mature Height: 4–6 feet
Mature Width: 3–5 feet
Bloom Season: Midsummer through late summer
Growth Rate: Slow to Moderate
Summary
Ruby Spice Summersweet fills a gap in the garden that few other shrubs can touch — fragrant, richly colored blooms in the heart of summer, even in shaded and wet conditions. The deep rose-pink flower spikes hold their color far better than other pink Clethra selections, which tend to fade to a washed-out tone as blooms mature.
The bottlebrush-style racemes open from late July into August, releasing a spicy-sweet fragrance that carries well beyond the immediate planting area. Butterflies, native bees, and hummingbirds respond strongly to the nectar-rich flowers, making this one of the best midsummer pollinator shrubs available. The glossy dark green foliage provides an attractive backdrop throughout the growing season and turns warm golden yellow in fall. Small, peppercorn-like seed capsules persist into winter for subtle textural interest.
Native to the swamps, marshes, and coastal woodlands of eastern North America, Summersweet is naturally adapted to moist, acidic soils and partial to full shade. Ruby Spice maintains a dense, compact habit and spreads slowly by root suckers, making it easy to manage in borders, foundations, and rain garden plantings.
Care
Ruby Spice Summersweet Care
Plant Ruby Spice in partial shade to full shade for the most attractive foliage. Full sun is tolerated in northern regions if consistent moisture is maintained. This shrub thrives in moist to wet, acidic soils rich in organic matter and adapts well to clay, sandy, and loamy conditions. It tolerates occasional standing water and is an excellent choice for low-lying areas and rain gardens.
Water consistently, especially during establishment and in drier sites. While mature plants handle brief dry spells, Summersweet performs best with reliable moisture. A layer of organic mulch helps retain soil moisture and maintain the acidic conditions this shrub prefers. Fertilize lightly in spring with a slow release fertilizer formulated for acid-loving plants if growth seems slow.
Prune in late winter or early spring before new growth begins. Clethra blooms on new wood, so spring pruning does not reduce flowering. Remove any dead or crossing stems and thin suckers if the plant is spreading beyond its intended footprint.
Size
What Size is the Ruby Spice Summersweet for Sale Online?
Our Ruby Spice Summersweet ships in a greenhouse-grade grow pot and is appropriately sized for its container at the time of shipment. If you have specific sizing or planting questions, please contact us.
How Large Does Ruby Spice Summersweet Grow?
Ruby Spice typically reaches 4 to 6 feet tall and 3 to 5 feet wide. It spreads gradually by root suckers and can form a small thicket over time if not managed.
Additional Information
What are some common names for this plant?
This plant is commonly known as Ruby Spice Summersweet, Sweet Pepperbush, and Summersweet Clethra. The name Sweet Pepperbush refers to the small, peppercorn-like seed capsules that follow the flowers.
Is Ruby Spice Summersweet a native plant?
Ruby Spice is a nativar — a cultivar selected from the native species Clethra alnifolia, which is indigenous to eastern North America from Maine to Florida. It retains the ecological value and site adaptability of the straight species while offering deeper pink flower color. It is a strong addition to Native Plants of North America gardens.
Can Ruby Spice grow in wet soil?
Yes. Clethra alnifolia naturally grows in swamps, wet woodlands, and coastal marshes. Ruby Spice handles consistently moist to wet conditions and is an excellent choice for rain gardens, stream banks, and low-lying areas where drainage is poor.
Is Ruby Spice Summersweet deer resistant?
Yes. Summersweet is widely regarded as deer resistant and is rarely browsed. This makes it a reliable choice for shaded landscapes with deer pressure. Explore our Deer-Resistant Shrubs and Evergreens collection for more options.
