Light Needs
Mature Height
Mature Spread
Growing Zones
Summer Sparkler Summersweet, Summer Sweet, Einstein Summersweet, Novacleein, or Clethra Alnifolia, is a compact, heavy-blooming, deciduous shrub packed with 12-inch floriferous spires of twisted, fragrant blooms, reminiscent of Albert Einstein’s trademark hair. These racemes, that bloom in spades during the early to midsummer, are bursting with tiny white flowers which have a spicy, intoxicating aroma. Summer Sparkler Summersweet grows to a height of 3 to 4 feet with a spread of 3 to 4 feet and is named for the fluttering lights of sparkler fireworks. This variety of summersweet offers seasonal interest with glossy, green leaves appearing in late spring.
Native to the United States, the Summer Sparkler Summersweet has dense, compact branches that form a soft mound. The snow-white flowers of this summersweet are an important summer source of nectar to critical pollinators, and attract butterflies and hummingbirds. It makes an excellent groundcover and is deer and critter resistant. Summer Sparkler is an excellent, hardy option for shady areas, and it is tolerant of wet and salty sites.
Summer Sparkler Summersweet Care
The Summer Sparkler Summersweet performs best in partial sun, but can adapt to both full sun and dappled shade. The best type of soil for your Summer Sparkler Summersweet is organic, slightly acidic, and well-drained, but it can thrive in many types of soil. It will need regular watering to thrive, especially while it establishes.
To prune your Summer Sparkler Summersweet, cut old wood from the base in the late winter or early spring before new growth begins. It should be fertilized yearly in the early spring.
Summer Sparkler Summersweet Spacing
The Summer Sparkler Summersweet should be spaced 4 to 6 apart at planting. They make a great single specimen accent, or you can plant it en masse. Summer Sparkler is an excellent option grown anywhere you can enjoy its spicy, clove-like fragrance. It also makes a beautiful addition to a mixed shrub border.
Summer Sparkler™ Summersweet Plant Facts
Growing Conditions
- Hardiness ZonesGrowing Zones
- USDA Zones 4 to 8 (perennial); grown as an annual elsewhere (outdoors year-round); grown indoors elsewhere (outdoors year-round); grown in containers elsewhere (grown as a seasonal crop)
- Sun Exposure
- Full Shade to Full Sun (Most Sun Conditions)
- Mature Height
- 3-4 Feet
- Mature Spread
- 3-4 Feet
- Growth Rate
- Moderate
- Growth Habit
- , Upright, Mounded
- Water Needs
- Consistently Moist
Flowers & Foliage
- Flower Colors
- , White
- Flower Description
- White
- Bloom Time
- Mid to Late Summer
- Blooms On
-
New Wood
?
"Blooms on" tells you which stems produce flowers, which decides when it's safe to prune.
- New Wood: Flowers form on stems that grow this season. Prune in late winter or early spring without losing blooms.
- Old Wood: Flower buds form on last year's stems. Prune right after flowering. Pruning in fall or early spring removes next year's blooms.
- Both New and Old Wood: Blooms on last year's stems and again on new growth, so it flowers even after a hard winter or a mistimed pruning. Prune lightly after the first flush of blooms.
- When to Prune
- Late winter to early spring, before new growth starts
- Foliage Color
- , Green, Pink
- Foliage Description
- Green
- Foliage Type
- , Evergreen, Deciduous
- Seasonal Interest
- , Summer Flowering, 3 Season Interest, Fall Interest
Garden Benefits
Plant Overview
- Common Name
- Summer Sparkler™ Summersweet
- Also Known As
- Summer Sweet, Einstein Summersweet, Novaclean
- Botanical Name
- Clethra Alnifolia 'Summer Sparkler'
- Plant Type
- Shrub
Simple Plant Spacing Calculator
Please Note: The pictures below are to give a general representation of the different container sizes. The actual size/ages of plants are estimates and will vary based on type of plant, time of year, last pruning & many other factors.
Also Known As:
Quart
Plant Age:
~ 6 months - 1 year
Plant Size:
~ 4"-8"
Pot Size:
~ 4.75"H x 4.5"W
Volume:
1.50 quarts
Also Known As:
2.5 Quart Pot
Plant Age:
~ 1 - 2 years old
Plant Size:
~ 8"-12"
Pot Size:
~ 6.5"H x 6.5"W
Volume:
2.20-2.30 quarts
Also Known As:
#1 Container
1 Gallon
Plant Age:
~ 1 - 2 years old
Plant Size:
~ 10"-14"
Pot Size:
~ 7"H x 7.75"W
Volume:
2.26-3.73 quarts
Also Known As:
#2 Container
2 Gallon
Plant Age:
~ 1.5 - 3 years old
Plant Size:
~ 12"-18"
Pot Size:
~ 9.5"H x 9.5"W
Volume:
1.19-1.76 gallons
Also Known As:
#3 Container
3 Gallon
Plant Age:
~ 2 - 4 years old
Plant Size:
~ 12"-30"
Pot Size:
~9.5"H x 11"W
Volume:
2.32-2.76 gallons
Also Known As:
#5 Container
5 Gallon
Plant Age:
~3-4 years old
Plant Size:
~ 20" - 60"
Pot Size:
~11" H x 10 1/2” W
Volume:
3.5 - 4 gallons
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This plant cannot be shipped to the following states: AK, HI. These restrictions apply only to this specific plant due to agricultural regulations or other limitations. Other plants may still be available for shipping to these states.
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