| Botanic name | Acacia baileyana |
| Other names | Cootamundra wattle, Bailey’s wattle, golden mimosa |
| Main Origin | Southeastern Australia |
| Mature size | 3 – 4 m x 3 – 8 m (w x h) |
| Mature form | Upright shrub or small tree with a conical or round canopy |
| Foliage | Ferny, feathery, bluish or silvery green |
| Growth rate | Fast |
| Position | Full sun, part shade |
| Soil | Adapts to most soils |
| Water | Minimal, deep watering during extended dry periods |
| Climate | Semi-arid, Mediterranean, temperate, mild subtropical |
| Flower | Prolific, golden-yellow, spherical, winter to spring |
| Use | Feature specimen, informal screening, avenue planting |
| Notes | Suitable for coastal sites |
IN THIS ARTICLE
Overview
Acacia baileyana, or Cootamundra Wattle, is a small, striking evergreen tree or large shrub native to southeastern Australia. It is a striking ornamental plant, widely admired for its graceful, feathery silver-grey foliage and profuse bright golden-yellow flowers.
Acacia baileyana can grow in various soils and climates. It is highly popular in both urban and rural environments. However, its ability to self-seed and establish itself beyond cultivation has led to its invasiveness and caused serious concerns in many regions.
Origin and distribution
Acacia baileyana originates from a restricted region near Cootamundra in New South Wales, Australia. In its natural habitat, it typically grows in open woodlands, dry forests, and often near waterways or on undulating hills.
Due to its ornamental appeal, Cootamundra Wattle has been widely cultivated across Australia and many other countries. However, this plant has escaped cultivation and prospered in many regions far beyond its natural range.
It is now considered invasive in many parts of Australia and has become naturalised in other parts of the world, including New Zealand, southern Africa, and America.
Growth and care
Acaica baileyana originates from inland subtropical regions. With great adaptability, this plant thrives in various climates, from drier semi-arid and Mediterranean to temperate and subtropical climates.
This wattle species naturally occurs in well-drained, moderately moist soils, mostly stony or rocky. However, it can adapt to various soil types, so long as they have reasonable drainage and a slightly acidic to neutral pH.
This species is very drought-tolerant. It is well known for its ability to withstand extended dry periods, making it highly suitable for drought-prone gardens with low rainfall. While young plants require regular watering for the first few months, as a fast-growing species, it can soon establish itself without extensive care.
Cootamundra Wattle does not sustain extended freezing conditions. But it can tolerate frosts and low temperatures to -7°C. While it is not the first-line coastal species, this wattle exhibits some salt tolerance and is suitable for less exposed seaside gardens.
As a nitrogen fixer, Acacia baileyana can grow in nutrient-poor soils. However, this plant performs best in moderately fertile soils. Adding organic matter or compost can encourage healthy growth of young plants.
The plant thrives perfectly well without additional fertiliser, even in poor soil. Apply a slow-release, low-phosphorus fertiliser or compost if the plant shows stunted growth or sparse foliage.
Cootamundra Wattle has a stunning natural form and does not often require pruning. However, to accomplish a tree form, identify the central leader and remove lower side branches while the tree is young.
Features
Acacia baileyana is a fast-growing shrub or tree, typically reaching a height of 3 – 8 metres in cultivation and occasionally 10 metres if growing conditions are optimal.
The plant appears upright but stout, with a rounded, spreading canopy low to the ground. Its trunk is smooth, grey or brown, often rough or fissured with age. Its branches appear light and airy, giving the tree a soft and flowing structure.
The most distinctive feature of Cootamundra Wattle is its unique foliage, which is feathery, fern-like, bipinnate (twice divided into small leaflets), and silvery-grey or blue-green. These stunning leaves give the tree a delicate, shimmering look.
The refined texture and form of its foliage contribute significantly to the tree’s graceful appeal, and the cool tones contrast beautifully with its vibrant, fluffy flowers, making it a favourite in urban landscaping.
In late winter and early spring, bright golden-yellow spherical flowers emerge in profusion. These flowers are borne in dense clusters, sometimes so abundantly that they obscure the foliage. Seedpods follow after flowering.
The dazzling display of blooms provides a cheerful burst of colour during the cooler months, making Acacia baileyana a standout in winter gardens. Their vibrant colour and sweet fragrance also attract pollinators like bees and birds.
Varieties
Acacia baileyana offers varieties, each with unique ornamental appeal.
- Acacia baileyana ‘Purpurea’: Prized for its striking, persistent purplish new growth that contrasts with its mature silvery-blue foliage and bright yellow flowers.
- Acacia baileyana ‘Prostrate’: The prostrate variety that features stunning extensions of branches, reaching a height of 30 – 60 cm with a 2 – 4 metre spread.
- Acacia baileyana ‘Goldilocks’: A grafted dwarf cultivar featuring pendulous branches in a cascading form, reaching a height and width of 2 metres.
Environmental concerns
The tendency of Acacia baileyana to establish itself quickly in native bushland is a cause for concern. Like its close cousin, Acacia dealbata (Silver Wattle), it is a highly adaptable pioneer species that can become naturalised outside its natural range.
It is also a prolific seeder and able to sucker from roots. With similar distributions in Australia, both plants have hybridised to various degrees over time. Both plants are nitrogen fixers and can disrupt the nutrient balance of soils, impacting native vegetation adapted to low-nitrogen conditions.
While highly valued for their ornamental appeal, fast growth, and role in reforestation, their aggressive spread has caused serious concerns in Australia and abroad. Therefore, responsible cultivation is critical to prevent further spread and protect native biodiversity.
FAQs
What is the lifespan of Cootamundra Wattle?
Cootamundra Wattle (Acacia baileyana) typically lives up to 15 to 30 years, depending on its growing conditions. Its lifespan can be further shortened in harsh and dry climates.
As a fast-growing pioneer species, it establishes quickly and matures early, but this rapid growth often comes with a relatively short life expectancy.
Can you prune Cootamundra Wattle?
Yes, you can prune Cootamundra Wattle. Light pruning encourages compact growth and helps maintain its graceful form. Structural pruning in young trees can promote a single trunk development for a stunning specimen tree.
