Water gum

Sun

Full sun to partial shade; the canopy is usually denser in good light.

Water

Water regularly while establishing. Established trees tolerate some dry weather but grow best with deep watering during prolonged dry spells.

Soil

Moist, well-drained soil, preferably slightly acidic to neutral. Tolerates clay and occasional flooding, but avoid permanently stagnant, waterlogged ground.

Height

20-40 ft (6-12 m) in gardens; potentially taller in favourable conditions

Spread

15-30 ft (4.5-9 m)

Flowers

Small yellow flowers in clusters in summer, typically November-February in Australia and June-August in the Northern Hemisphere.

Foliage

Evergreen. Glossy, narrow oval, dark green leaves with paler undersides; young growth is often bronze or reddish.

Growth

Moderate with adequate moisture; slower in dry or cool conditions.

Care needed

Low

• Pollinators
• Heat tolerant
• Wildlife
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Hard

Toughness

Needs looking after

Pick your zone, country, light and whether you have pets.

1. Planting day

   7 ft (2 m)

2. After 1 year

   7 ft (2.3 m)

3. After 2 years

   8 ft (2.5 m)

4. After 3 years

   9 ft (2.8 m)

5. After 5 years

   11 ft (3.3 m)

About 26 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Safe

Native to

Australia

Growth rate

Slow

• Water deeply through the first two growing seasons, allowing the surface soil to begin drying between waterings.
• Spread 2-3 in (5-8 cm) of organic mulch over the root area, keeping it clear of the trunk.
• Choose a sheltered position away from frost pockets, especially near the cool edge of its range.
• Feed lightly in spring only if growth is weak or the soil is poor; avoid heavy fertilising.
• Stake only if the root ball moves in wind, using flexible ties and removing support once the tree is stable.

Pruning. In late winter or early spring, remove dead, damaged and crossing branches and gradually establish a sound framework on young trees. Avoid topping or removing large limbs unnecessarily; allow space for the mature canopy.

Spring

Plant after the risk of damaging frost has passed, setting the root flare at soil level.

Spring

Refresh mulch and check that stakes and ties are not rubbing or constricting the trunk.

Summer

Check soil moisture during hot weather and water young trees deeply rather than sprinkling daily.

Autumn

In mild, frost-free areas, plant while the soil is warm and autumn rain can help establishment.

Winter

Protect young trees with horticultural fleece during forecast frosts near the cool limit of their range.

Late winter

Inspect the branch structure and remove damaged or poorly placed small branches before spring growth.

• Use as a shade tree beside a lawn or terrace, leaving room for the mature crown and roots.
• Plant as a street or driveway tree where soil volume and overhead clearance are adequate.
• Combine with lomandra and native violet for a layered Australian-native garden.
• Use its evergreen canopy and pale bark as a backdrop to a contemporary courtyard large enough to accommodate it.

Garden styles it suits: Australian native, Modern, Urban city garden, Woodland, Wildlife garden and Green on green.

Plant it with: Lomandra, Dianella, Native violet, Bird's nest fern, Clivia and Cast-iron plant.

Wildlife: Flowers provide pollen and nectar for bees and other insects. The evergreen crown offers shelter and potential nesting sites for small birds.

• Frost damage: young shoots may blacken after freezing weather. Protect young trees and wait until spring growth reveals the extent of damage before pruning.
• Scale insects: inspect stems and leaf undersides if foliage becomes sticky or develops sooty mould. Treat small infestations with horticultural oil according to the label and control ants tending the scale.
• Root decline in stagnant soil: improve drainage and avoid frequent watering where the root zone remains saturated.
• Leaf scorch or premature leaf drop during drought: water deeply over the root area and maintain mulch, especially around recently planted trees.

Not known to be toxic to people, cats, dogs or horses. Species-specific toxicity information is limited, and no part should be treated as edible.

• Lemon myrtle (Backhousia citriodora)

  Lemon myrtle has opposite leaves with a strong lemon scent when crushed and creamy-white flowers; water gum has alternate leaves and yellow flowers.

• Sweet bay (Laurus nobilis)

  Sweet bay leaves have a distinctive culinary bay scent when crushed, and female plants can carry black berries. Water gum has small woody seed capsules and bark that flakes in patches.

Tristaniopsis means resembling Tristania, laurina means laurel-like, and water gum refers to its frequent occurrence beside streams.

Propagation. Sow fresh seed in a free-draining seed-raising mix and keep it moist and warm. Semi-ripe cuttings can also be tried, though rooting may be slow; named cultivars need vegetative propagation to retain their characteristics.

Accepted botanical name

Tristaniopsis laurina

Native range

New South Wales, Queensland and Victoria.

Sources: GBIF (CC BY 4.0) and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.