1 named cultivar
The Story
Plant Bio
Tristaniopsis laurina, the water gum, is an upright, evergreen tree native to eastern Australia that reaches twenty to fifty feet in height, featuring smooth, pale grey bark that peels away in strips to reveal a mahogany underlayer. The narrow, glossy deep green leaves emerge with a copper-bronze coloration and crowd the branch tips, providing a dense, rounded canopy year-round.
Clusters of small, bright yellow flowers with five rounded petals bloom in the leaf axils from late spring into summer, releasing a sweet scent that draws bees and other insect pollinators. The species is highly resistant to coastal winds, salt spray, and urban air pollution, making it a reliable street tree in mild climates.
Uses & Benefits:
Essentials
At a Glance
Plant Type
Tree
Height
480"
Width
240"
Light
Full Sun, Partial Sun
Zones
9, 10
Water
Moderate
Humidity
High
Lifespan
Long-lived
Native To
Australia
Toxicity
Non-toxic
Planting
How to Grow
- Select a planting site in full sun to partial shade with moist, well-draining soil.
- Dig a hole twice as wide as the root ball and of equal depth, ensuring the crown sits level with the surrounding soil.
- Water deeply and regularly during the first two growing seasons to establish a deep root system.
- Apply a layer of organic mulch around the base to retain moisture, keeping it clear of the trunk.
Pro Tip
Avoid planting in stagnant, waterlogged clay; while this species thrives along moist stream banks in the wild, it requires moving water or oxygenated, well-drained soil to prevent root rot.
Keep It Thriving
Care Guide
Do
- Water regularly during dry spells to maintain consistent soil moisture.
- Prune lightly in late winter to shape the canopy or clear lower branches.
- Apply a balanced, slow-release fertilizer in spring if growth appears sluggish.
Don't
- Do not allow the roots to sit in stagnant, poorly drained water.
- Avoid heavy pruning into old, leafless wood lacking active buds.
- Do not starve the tree under the assumption that all Australian natives are highly phosphorus-sensitive.
Seasonal Care Calendar
| Task | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Fertilize | ||||||||||||
| Mulch | ||||||||||||
| Pest Check | ||||||||||||
| 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
Water Gum questions
What zones can Water Gum grow in?
Water Gum 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 Water Gum deer resistant?
Not reliably. Deer may browse Water Gum, especially tender spring growth — plan on repellents or fencing where pressure is high.
When does Water Gum bloom?
Water Gum typically blooms in late spring through summer. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.
Does Water Gum need full sun?
Water Gum does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.
Is Water Gum drought tolerant?
Yes — once established (usually after the first full season), Water Gum handles dry spells with minimal watering. Water deeply its first year to build the root system that makes that possible.
Keep exploring
Explore the genus
Hardy in your zone?
Grow Water Gum 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.