Sydney golden wattle

Sun

Full sun; tolerates light shade but flowers less freely.

Water

Water regularly while establishing; once rooted, it tolerates dry spells and usually needs watering only during prolonged drought.

Soil

Well-drained sandy or loamy soil, preferably acidic to neutral. Tolerates poor soils but dislikes waterlogging and can develop yellow foliage on strongly alkaline ground.

Height

10-26 ft (3-8 m)

Spread

10-20 ft (3-6 m)

Flowers

Small, golden-yellow flowers packed into cylindrical spikes in late winter and spring; usually February-April in the Northern Hemisphere and July-October in Australia, depending on climate.

Foliage

Evergreen. Long, narrow, leathery green phyllodes—flattened leaf stalks that function as leaves—with several prominent lengthwise veins.

Growth

Fast

Care needed

Medium

• Pollinators
• Drought tolerant
• Heat tolerant
• Wildlife

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

Difficulty

Hard

Toughness

Fairly tough

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 13 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

Invasive in

the US

In the garden

Spreads vigorously: plan to contain it.

Growth rate

Fast

• Plant in spring in frost-prone districts, or autumn where winters are mild and wet.
• Water deeply through the first growing season, allowing the surface soil to dry between waterings.
• Apply a loose mulch over the root area, keeping it clear of the trunk.
• Avoid routine feeding; if growth is poor, use a low-phosphorus fertiliser formulated for Australian native plants.
• Choose a freely draining site with shelter from severe frost, and remove unwanted seedlings promptly.

Pruning. Immediately after flowering, lightly shorten young shoots to encourage branching and remove damaged or crossing branches. Avoid hard cuts into old, bare wood, which may not regrow reliably.

Late winter

Enjoy the first flowers and check young plants for frost damage; delay cutting damaged growth until frost risk has passed.

Spring

Plant in cooler districts and water new plants deeply.

Late spring

Lightly prune after flowering; remove developing pods where preventing seed spread is important.

Summer

Water establishing plants during dry weather and inspect stems for scale insects.

Autumn

Plant in mild-winter districts, renew mulch and pull seedlings while small.

Winter

Protect young plants during brief severe frosts and check that water drains freely around the roots.

• Use as an informal evergreen screen where there is room for its broad crown.
• Plant as a small specimen tree, with the yellow flowers standing out against darker evergreen shrubs.
• Combine with bottlebrushes, lomandras and native grasses in an Australian planting.
• Use in coastal gardens on well-drained ground for shelter and seasonal colour, only where it is not invasive.

Garden styles it suits: Australian native, Coastal, Mediterranean, Wildlife garden, Desert / xeriscape and Winter interest.

Plant it with: Crimson bottlebrush, Coastal rosemary, Spiny-headed mat-rush, Kangaroo grass and Flax-leaf paperbark.

Wildlife: Flowers provide pollen for bees and other insects. Dense branches offer cover for small birds, and seeds are eaten by some birds and ants. Outside its native range, dense stands can displace local vegetation and reduce habitat diversity.

• Root rot in wet soil: improve drainage before planting and avoid frequent watering of established trees; badly affected plants may need replacing.
• Scale insects and associated sooty mould: inspect stems, control ants and treat accessible infestations with horticultural oil according to the label.
• Frost damage to young shoots: choose a sheltered position, cover small plants during cold snaps and prune dead tips after frost risk passes.
• Unwanted seedlings: remove pods before they mature where practical and pull seedlings promptly, especially after soil disturbance or fire.

Not generally known as a poisonous garden plant, but reliable species-specific information for cats, dogs and horses is limited. Do not let pets or livestock browse it, and do not eat foliage, pods or untreated seeds; traditional food uses do not establish that raw plant material is safe.

Where it spreads. Invasive in Portugal, parts of Spain, South Africa, New Zealand and coastal California. It is also an environmental weed outside its native range in parts of Australia, including Western Australia and South Australia. Long-lived soil seed banks make established infestations difficult to remove; check local restrictions before planting.

• Coast wattle (Acacia longifolia subsp. sophorae)

  Usually a lower, spreading coastal shrub with broader, often blunt-tipped phyllodes; Sydney golden wattle is generally more upright with longer, narrower phyllodes.

• Flax-leaf wattle (Acacia linifolia)

  Has much narrower phyllodes and pale cream flowers in round heads rather than golden cylindrical spikes.

• Golden wattle (Acacia pycnantha)

  Has broader, curved phyllodes and round golden flower heads rather than elongated flower spikes.

The botanical name longifolia means 'long-leaved', referring to its elongated phyllodes, while Sydney golden wattle links its golden flowers with part of its native Australian range.

Propagation. Where planting is appropriate and permitted, grow from seed after nicking the hard seed coat or pouring hot water over it and allowing it to soak as the water cools. Sow swollen seeds in a freely draining mix and protect young plants from frost.

Accepted botanical name

Acacia longifolia

In the US and Canada

Introduced in the lower 48 states.

Native range

New South Wales, South Australia, Tasmania and Victoria.

Measured

Average height 470 cm.

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