Clethra alnifolia 'Summer Sparkler' is a compact fragrant summersweet cultivar that produces dense spikes of white flowers in mid to late summer. Its bottlebrush blooms emit a sweet fragrance that attracts pollinators while its glossy green foliage transitions to rich golden yellow in fall. This variety is particularly valued for its long bloom period and suitability for smaller gardens or naturalized woodland plantings.
Height & Spread: 3 - 4 ft x 3 - 4 ft
Bloom Time: Mid to late summer
Light Requirements: Full sun to part shade
Soil Preference: Moist, acidic, well drained soil
Watering Needs: Moderate; prefers consistent moisture
Deer Resistance: Generally deer resistant due to aromatic foliage
Native Status
Clethra alnifolia is native to eastern North America, commonly found in wetlands, woodland edges, and coastal areas. 'Summer Sparkler' is a cultivated form with enhanced ornamental qualities but retains the ecological value of the species.
WILDLIFE & INSECTS
Bees
- Highly attractive to native bumblebees, honeybees, and small solitary bees that feed on its nectar rich blooms.
Butterflies
- Frequented by swallowtails, painted ladies, and other summer butterflies seeking abundant nectar sources.
Moths
- Fragrant blooms draw in evening pollinators like sphinx moths and noctuid species after dusk.
Birds
- Provide cover for small birds such as wrens and sparrows; seed heads attract finches in late summer and fall.
Beneficial Insects
- Supports hoverflies and parasitic wasps that help control garden pests during the warm season.
Spacing & Landscape Use
Spacing Recommendations:
- Plant 3 - 5 ft apart to allow full spread and maintain airflow between shrubs.
Landscape Placement:
- Excellent for woodland gardens, foundation plantings, and along water features or moist borders where fragrance and wildlife value can be enjoyed.
Companion Plants
- Rhododendron periclymenoides (Pinxterbloom Azalea) - Deciduous azalea with soft pink spring blooms pairs well with Clethra's summer flowers.
- Vaccinium corymbosum (Highbush Blueberry) - Offers edible berries, seasonal interest, and thrives in similar acidic soils.
- Osmunda cinnamomea (Cinnamon Fern) - Provides lush green fronds in moist soil enhancing woodland or wetland plantings.
- Carex muskingumensis (Palm Sedge) - Adds a graceful texture and thrives in the consistently moist conditions preferred by Clethra.
- Itea virginica 'Little Henry' - Compact native shrub with fragrant white flowers and brilliant fall color complements Clethra in size and habit.