River wattle Limelight

Sun

Full sun to partial shade; light afternoon shade is helpful in hot inland gardens.

Water

Water regularly while establishing, then deeply during extended dry spells. Allow the soil surface to dry between waterings; container plants need more frequent checks.

Soil

Well-drained sandy or loamy soil, preferably slightly acidic to neutral. Avoid waterlogged clay and persistently wet planting sites.

Height

3-5 ft (0.9-1.5 m)

Spread

3-5 ft (0.9-1.5 m)

Foliage

Evergreen. Narrow, soft-looking, lime-green phyllodes—flattened leaf stalks that function as leaves—on slender, arching branches. Colour is usually brightest on new growth.

Growth

Moderate

Care needed

Low

• Drought tolerant
• Heat tolerant
• Wildlife
• Low allergen

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

Difficulty

Moderate

Toughness

Fairly tough

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

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   2.1 ft (0.64 m)

3. After 2 years

   2.6 ft (0.78 m)

4. After 3 years

   3 ft (0.92 m)

5. After 5 years

   4 ft (1.2 m)

   full size

About 5 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

Moderate

• Water deeply through the first growing season, allowing excess water to drain away.
• Keep a light organic mulch over the root area, clear of the stem base.
• Feed sparingly in spring with a low-phosphorus fertiliser suitable for Australian native plants.
• Shelter from cold, drying winds and protect young plants from frost.
• Use a free-draining potting mix in containers and never leave the pot standing in water.

Pruning. Lightly tip-prune in spring, once frost danger has passed, to maintain a dense, rounded outline. Remove dead branches, but avoid hard cutting into old, leafless wood because regrowth can be unreliable.

Spring

Plant after frost danger has passed, water thoroughly and mulch around the root area.

Late spring

Lightly trim long shoots and apply a modest amount of low-phosphorus fertiliser if growth is weak.

Summer

Check young and container-grown plants regularly; water deeply when the root zone begins to dry.

Autumn

Check drainage before wetter weather and clear fallen debris from the centre of the shrub.

Winter

Protect from hard frost; move containers under bright, frost-free cover where winters are too cold.

• Use as a soft, rounded foliage accent beside paths, allowing enough room for branches to spread without repeated clipping.
• Plant in a large container where its fine foliage can spill over the rim.
• Contrast its lime-green foliage with dark-leaved shrubs and upright grasses.
• Repeat in a well-drained Australian-native border for a consistent, flowing texture.

Garden styles it suits: Australian native, Contemporary minimal, Modern courtyard, Green on green, Small-space and Mediterranean.

Plant it with: Kangaroo paw, Lomandra, Flax lily, Coastal rosemary, Grevillea and Correa.

Wildlife: The dense branching can provide shelter for small birds and invertebrates. This cultivar flowers little or irregularly, so it is not a dependable source of nectar or pollen.

• Root rot and sudden decline in wet soil: improve drainage before planting, avoid overwatering and replace badly affected plants rather than replanting into the same wet conditions.
• Frost scorch: choose a sheltered site, cover young plants during cold snaps and wait until spring to remove damaged growth.
• Scale insects: inspect stems and treat small infestations with horticultural oil according to the label, avoiding hot weather.
• Brown foliage from drought or drying winds: check soil moisture, water the root zone deeply and provide shelter; do not assume every browning plant needs more water.

Not known to be toxic to people, cats, dogs or horses, but reliable toxicity information specifically for this cultivar is limited. No particular part is established as poisonous; it is not a food plant, so discourage chewing or eating the foliage, bark or seeds.

• River wattle (Acacia cognata)

  The ordinary species develops into a much larger shrub or small tree, usually with greener foliage; 'Limelight' remains a compact, lime-green mound.

• Sticky wattle (Acacia howittii)

  It also has fine, drooping foliage, but its phyllodes are generally shorter and broader and often sticky to the touch.

The cultivar name 'Limelight' refers to its bright lime-green foliage.

Propagation. Propagate from semi-ripe cuttings in summer, preferably with gentle bottom heat; rooting can be variable. Seed will not reliably reproduce 'Limelight'. Check local plant breeders' rights restrictions before propagating.

Accepted botanical name

Acacia cognata

Native range

New South Wales and Victoria.

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