Summersweet
Clethra alnifolia is commonly known as Summersweet or Sweet Pepperbush. Summersweet produces large late summer blooms that are colorful and fragrant. Summersweet has the unique ability to bloom in shade. This medium sized deciduous shrub is very versatile.
Summersweet Clethra alnifolia ‘Hummingbird’
Hardiness Zones: Zones 3-9
Light Requirements: Part Shade to part sun. Tolerates full shade.
Water Requirements: Prefers average to wet conditions
Mature Height: 2-4 feet
Mature Spread: 3-5 feet
Shape: Dense and rounded.
Growth Rate: Slow
Soil Preference: Prefers consistently moist acidic soil. Will tolerate clay and wet soil.
Foliage: Glossy dark green leaves turn golden yellow in autumn.
Blooms: Creamy white blooms from July to August
Fruit: Clusters of deep blue-black berries are of minimal significance.
Disease and Insects: Not generally affected by disease or pests. Spider mites may occasionally be a problem in dry conditions.
Fertilize: Apply a balanced slow release fertilizer in spring
Pruning: Prune in late winter or spring if needed.
‘Hummingbird’ is a compact and slow spreading cultivar that generally remains about three to four feet tall. One of the most floriferous of the Summersweets, the showy bottlebrush spikes of blooms with a lovely clove fragrance. Blooming late in the season, Summersweet continues to attract butterflies and bees well into autumn. The blooms mature to dark brown fruit that persists into winter.
A perfect Summersweet for small gardens or the front of a shrub border or foundation planting. In a shady woodland garden “Hummingbird’ is rarely bothered by deer. Allow suckers to spread in naturalized areas, otherwise remove the occasional root suckers as they appear. Flowers on new wood, so prune in very late winter or spring. Very tolerant of urban conditions and thrives in inner city environments.
Summersweet Clethra alnifolia ‘Ruby Spice’
Hardiness Zones: Zones 4-9
Light Requirements: Part Shade to part sun. Tolerates full shade.
Water Requirements: Prefers average to wet conditions
Mature Height: 4-6 feet
Mature Spread: 3-5 feet
Shape: Dense and rounded.
Growth Rate: Slow
Soil Preference: Prefers consistently moist acidic soil. Will tolerate clay.
Foliage: Glossy dark green leaves turn yellow and golden brown in autumn.
Blooms: Rose pink blooms from July to August
Fruit: Large clusters of deep blue-black berries
Disease and Insects: Not generally affected by disease or pests. Spider mites may occasionally be a problem in dry conditions.
Fertilize: Apply a balanced slow release fertilizer in spring
Pruning: Prune in late winter if needed.
‘Ruby Spice’ was discovered as a sport of ‘Pink Spire’. Highly fragrant rose pink bottlebrush like spikes of blooms appear in late summer when most flowering shrubs are fading. The bloom's fragrance will last up to six weeks in late summer. Preferring part sun to shady conditions ‘Ruby Spice’ can offer colorful late summer blooms to your shady areas. The foliage glows golden yellow in autumn.
In ideal conditions ‘Ruby Spice’ may reach 8 feet tall and 8 feet wide or more. In full sun and hotter regions ‘Ruby Spice’ will need constant moisture. A great compact shrub in cottage gardens, shrub borders or foundation plantings. Summersweets will sucker and root suckers should be pruned other than in naturalized areas or along stream banks.The flowers attract hummingbirds and butterflies.
Summersweet Clethra alnifolia ‘Caleb’ Vanilla Spice
Hardiness Zones: Zones 4-8
Light Requirements: Part Shade to part sun. Tolerates full shade.
Water Requirements: Prefers average to wet conditions
Mature Height: 3-6 feet
Mature Spread: 3-5 feet
Shape: Rounded
Growth Rate: Slow
Soil Preference: Prefers consistently moist acidic soil. Will tolerate clay and wet soil.
Foliage: Glossy dark green leaves turn golden yellow to golden brown in autumn.
Blooms: Pure white blooms from July to August
Fruit: Clusters of dark brown seed capsules are of minimal significance.
Disease and Insects: Not generally affected by disease or pests. Spider mites may occasionally be a problem in dry conditions.
Fertilize: Apply a balanced slow release fertilizer in spring
Pruning: Prune in late winter or spring if needed.
The highly fragrant blooms of ‘Vanilla Spice’ have extra large florets with individual blooms twice the size of most Summersweet varieties. Upright panicles are generally upright and 10 to 12 inches long. This is one of the most fragrant deciduous shrubs so enjoy the sweet scent by planting it near the entry of your home or alongside a garden bench or patio.
‘Caleb’ will often be found marketed as Vanilla Spice. It is very densely branched and will sucker, perfect for stream beds and naturalized areas. Lovely in a cottage garden, mixed border or a foundation planting. To prevent spreading root suckers should be pruned off below the soil line. The shrub is resistant to deer and attracts hummingbirds and butterflies.