
Summersweet
Clethra alnifolia 'Caleb'
Not currently listed at our partner nurseries.
Essentials
At a Glance
Plant Type
Shrub
Height
60 inches
Width
60 inches
Light
Full Sun, Partial Sun, Shade
Zones
4, 5, 6, 7, 8, 9
Water
High
Humidity
High
Lifespan
Long-lived
Native To
Eastern North America (species)
Toxicity
Non-toxic
The Story
Plant Bio
Clethra alnifolia, commonly known as summersweet, is a deciduous native shrub prized for its fragrant summer flowers that bloom even in shady locations. It typically has attractive yellow fall color. 'Caleb' (marketed as Vanilla Spice) is distinguished by its exceptionally large, pure white flower spikes, which can be twice the size of the species. The fragrance is intensely sweet and spicy.
Bloom Period:
Uses & Benefits:
Marketplace
Where to Buy
We couldn't find this plant listed online right now.
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Planting
How to Grow
- Select a site with moist, acidic soil in sun or shade.
- Amend soil with compost or peat moss to increase acidity and moisture retention.
- Dig a hole twice the width of the root ball.
- Place the plant in the hole, backfill, and water well.
- It flowers on new wood, so prune in early spring if needed.
- Mulch with pine straw or shredded leaves to maintain soil moisture.
Pro Tip
Plant near a patio or window where its delightful summer fragrance can be fully appreciated.
Keep It Thriving
Care Guide
Do
- Provide consistently moist soil.
- Mulch well to keep roots cool and moist.
- Prune in early spring before new growth begins to shape the plant.
- Plant in groups for a stunning floral and fragrant display.
Don't
- Don't let the soil dry out, especially in summer.
- Avoid planting in alkaline soils, which causes yellowing leaves.
- Don't prune after new growth starts, as this will remove flower buds.
- Avoid heavy fertilization.
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fertilize | ||||||||||||
| Mulch | ||||||||||||
| Plant | ||||||||||||
| 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.
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