The Story
Plant Bio
Agonis flexuosa is an evergreen tree native to southwestern Australia, characterized by a weeping growth habit and aromatic, willow-like foliage that releases a strong peppermint scent when crushed. In spring and summer, it produces small, five-petaled white flowers with dark centers clustered along the pendulous branches.
'After Dark' is a slow-growing cultivar distinguished by its deep burgundy to near-black foliage, which emerges with bright scarlet tones on new growth. It maintains a smaller, more compact stature than the wild species, reaching fifteen to twenty-five feet in height with an open, airy canopy.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Tree
Height
240"
Width
144"
Light
Full Sun, Partial Sun
Zones
9, 10
Water
Low to Moderate
Humidity
High tolerance to coastal humidity
Lifespan
Moderate
Native To
Southwestern Australia
Toxicity
Non-toxic, but aromatic oils can cause mild stomach upset if ingested in large quantities by pets
Bloom period
Spring – Summer
In flower about 6 months of the year
Planting
How to Grow
- Select a planting site in full sun to partial shade with highly permeable, well-draining soil.
- Dig a hole twice as wide as the root ball but equal in depth to prevent the crown from settling too deep.
- Water deeply immediately after planting and maintain regular moisture until the root system is established.
- Apply a thin layer of organic mulch around the base, keeping it clear of the trunk to prevent rot.
Pro Tip
Provide shelter from hot, dry winds and intense afternoon sun in inland zones to prevent the dark foliage from looking sparse or scorched. Avoid shearing into old, leafless wood, as this cultivar fails to regenerate from bare branches.
Keep It Thriving
Care Guide
Do
- Water deeply but infrequently during dry summer periods once established.
- Apply a low-phosphorus, slow-release fertilizer in early spring if growth is sluggish.
- Protect young trees from frost when temperatures drop below 28 degrees Fahrenheit.
Don't
- Do not plant in heavy, poorly drained clay soils where water pools.
- Do not prune heavily into old, bare wood lacking active foliage.
- Do not over-fertilize with high-phosphorus formulas.
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fertilize | ||||||||||||
| Pest Check | ||||||||||||
| Prune | ||||||||||||
| Winter Prep |
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
Peppermint Willow questions
What zones can Peppermint Willow grow in?
Peppermint Willow is hardy in USDA Zones 9–10. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.
Is Peppermint Willow deer resistant?
Yes — Peppermint Willow is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.
When does Peppermint Willow bloom?
Peppermint Willow typically blooms in spring through summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Peppermint Willow need full sun?
Peppermint Willow does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
Is Peppermint Willow drought tolerant?
Yes — once established (usually after the first full season), Peppermint Willow handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.
More Agonis to compare
Keep exploring
Explore the genus
Hardy in your zone?
Grow Peppermint Willow 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.