Clethra alnifolia ‘Sixteen Candles’
Overview
Uses: Pollinator gardens, mixed borders, mass plantings, rain gardens, and part-shade beds.
Benefits: A compact native summersweet with upright, candle-like spikes of very fragrant white flowers in midsummer, when few shrubs bloom. A pollinator favorite that handles wet soil and part shade, with yellow fall color.
USDA Hardiness Zones: 4–9
Sun: Full Sun to Partial Shade
Life Cycle: Deciduous Shrub
Growth Habit: Rounded, Upright — compact and dense.
Bloom Color: White (very fragrant)
Foliage Color: Glossy Green, turning Yellow in fall
Mature Height: 2.5–3 feet
Mature Width: 3–4 feet
Bloom Season: Midsummer
Growth Rate: Moderate
Summary
Sweet fragrance in the middle of summer, right when most shrubs have finished.
Summersweet earns its name. In midsummer, after the spring shrubs are done and before fall color arrives, Sixteen Candles sends up dozens of upright white flower spikes that stand above the foliage like candles on a cake. Their scent is sweet and spicy and carries well on warm, still evenings.
This is a compact form of a shrub that can grow much larger in the wild. It stays around two and a half to three feet tall and a bit wider, with dense, glossy green leaves, so it fits along the front of a border, under windows, or in groups along a path. In fall the foliage turns a clear yellow.
Bees and butterflies crowd the flowers while they are open, and because it comes from a species native to the eastern United States, it fits naturally into native and pollinator plantings. It is also one of the few flowering shrubs that takes wet soil and partial shade in stride, which makes it a strong choice for rain gardens, low spots, and the shady side of a house.
Care
Sixteen Candles Summersweet Care
Plant in full sun to partial shade. More sun brings heavier flowering; in partial shade the plant still blooms well, with slightly looser growth.
Summersweet prefers moist, acidic to neutral soil with some organic matter. It tolerates heavy, wet ground and periodic flooding, but struggles in hot, dry, or alkaline sites.
Water deeply once or twice a week through the first growing season while roots establish, and during summer dry spells after that. Consistent moisture is the single biggest factor in how well it grows. A two-to-three-inch layer of mulch helps hold that moisture.
Feeding needs are light. One application of a slow release fertilizer in early spring is plenty.
Summersweet blooms on new wood, so prune in late winter or early spring if needed. It leafs out late in spring, so do not mistake bare stems in April for winter damage. Over time it fills in slowly by suckers from the base; leave them to build a fuller mass, or trim them to keep the plant in a tighter footprint.
Size
What Size is the Sixteen Candles Summersweet for Sale Online?
Our Sixteen Candles Summersweet ships in a greenhouse-grade grow pot and is appropriately sized for its container at the time of shipment. Plants ship dormant or near dormant in the off-season, so they may arrive with few or no leaves. If you have specific sizing or planting questions, please contact us.
How Large Does Sixteen Candles Summersweet Grow?
Expect about 2.5 to 3 feet tall and 3 to 4 feet wide at maturity, in a dense, rounded shape. Space plants about 3 feet apart for a low mass planting or informal hedge.
Additional Information
What are some common names for this plant?
It is most often called summersweet, and is also known as sweet pepperbush for its peppercorn-like seed capsules.
Is Sixteen Candles Summersweet a native plant?
It is a selection of Clethra alnifolia, which is native to the eastern United States, from Maine to Florida and west to Texas. Selections like this one are often called nativars: they keep the fragrance and pollinator value of the native species in a smaller, more garden-friendly size. Browse more Native Plants of North America.
Will it grow in wet soil or shade?
Yes. Summersweet grows naturally in swamps, stream banks, and moist woods, so it handles wet soil and partial shade better than most flowering shrubs. It is a dependable choice for rain gardens, drainage swales, and shady foundation beds that stay damp. For more flowering shrubs, see our Shrubs & Bushes.
Do deer eat summersweet?
Deer usually pass summersweet by. No plant is completely deer-proof, and hungry deer may nibble young growth, but it is a reliable choice where deer are common. See more Deer-Resistant Shrubs and Evergreens.
