Summersweet
Clethra alnifolia 'Crystalina'
Essentials
At a Glance
Plant Type
Shrub
Height
36 inches
Width
36 inches
Light
Full Sun, Partial Sun
Zones
4, 5, 6, 7, 8, 9
Water
Medium to wet
Humidity
High
Lifespan
20+ years
Native To
Eastern North America
Toxicity
Non-toxic
The Story
Plant Bio
Clethra alnifolia is a deciduous shrub native to eastern North America, prized for its wonderfully fragrant summer flowers that bloom when few other shrubs do. It thrives in moist, acidic soils and has attractive yellow fall color. 'Crystalina' (also known as Sugartina) is a compact, dwarf selection with a tidy, rounded habit. It produces an abundance of pure white, fragrant flower spikes and is perfect for small gardens and containers.
Bloom Period:
Uses & Benefits:
Marketplace
Where to Buy
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Planting
How to Grow
- Select a site with full sun or partial shade and moist, acidic soil.
- Dig a hole twice as wide as the container and just as deep.
- Amend heavy clay or alkaline soils with compost or peat moss.
- Gently tease the roots and place the plant in the hole.
- Backfill the hole, ensuring the crown is level with the soil surface.
- Water deeply and apply a layer of mulch to conserve moisture.
Pro Tip
Plant in a location with consistently moist soil to prevent leaf scorch and ensure the most prolific, fragrant blooms.
Keep It Thriving
Care Guide
Do
- Provide consistent moisture, especially in the first year and during dry spells.
- Use an acidic mulch like pine needles or shredded bark.
- Plant in groups to maximize the fragrant effect.
- Prune in late winter or early spring, as it flowers on new wood.
- Allow it to naturalize and form a small colony if space permits.
Don't
- Do not let the soil dry out completely.
- Avoid planting in high pH (alkaline) soils, which causes yellowing leaves.
- Don't prune after new growth starts in spring, or you'll remove flower buds.
- Avoid deep cultivation around the shallow roots.
- Don't worry if it's one of the last shrubs to leaf out in spring.
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fertilize | ||||||||||||
| Mulch | ||||||||||||
| Prune |
Watch Out For
Pests & Diseases
Common Pests
Common Diseases
In the Garden
Landscape Uses & Companions
Landscape Uses
Companion Plants
Multiply
Propagation Methods
Good to Know
Common Questions
Summersweet questions
What zones can Summersweet grow in?
Summersweet is hardy in USDA Zones 4–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Summersweet deer resistant?
Yes — Summersweet is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does Summersweet bloom?
Summersweet typically blooms in mid-summer through late summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Summersweet need full sun?
Summersweet does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
More Clethra to compare
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Clethra alnifolia 'Caleb'
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Clethra alnifolia 'Ruby Spice'
Summersweet
Clethra alnifolia
Hummingbird Summersweet
Clethra alnifolia 'Hummingbird'
Einstein Summersweet
Clethra alnifolia 'Einstein'
Keep exploring
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Grow Summersweet with confidence
See it in a design of your actual yard, get zone-matched care reminders, and track it season by season in your garden journal.
