Type of weed: Woody weed
Flower colour(s): Yellow
Priority Weed Local Priority Weed. (See more weeds of the Local Priority Weed class.)
Flowering Months: June, July, August, September, October
A shrub or small tree 4–8 m high. Branchlets have a waxy coating.
Leaves are ‘feathery’, bipinnate (twice divided), silvery-blue to blue-green in colour and crowded on the stem.
It has many spike-like clusters of bright yellow, fluffy, fragrant flower heads. It flowers winter to early spring.
The plant produces many pods that are flattish and mature to brown or black. Seeds are long lived in the soil.
Note: Cootamundra Wattle is a native plant originating in the Cootamundra-Wagga Wagga area (southern NSW), but has become invasive outside its original range. It is often mistaken for local wattles and planted in gardens.
Don’t confuse with…
Cootamundra Wattle can be confused with similar local native bipinnate wattles such as Acacia parramattensis in the lower Mountains and Acacia terminalis in the mid to upper Mountains.
Seed is dispersed by birds, ants, machinery and in dumped garden waste.
Impact on bushland
Cootamundra Wattle is fast growing and a prolific producer of seeds. It moves into intact bushland displacing local wattles. Some infestations are scattered. Where it forms dense stands, it shades out local native plants. It also fixes nitrogen in the soil, making it unsuitable for the germination of many native plants.
Lower Blue Mountains, Upper Blue Mountains
Plant local native wattles such as:
- Acacia parramattensis
- Black Wattle (Acacia decurrens)
- Sydney Golden Wattle (Acacia longifolia)
- Sunshine Wattle (Acacia terminalis)
- Prickly Moses (Acacia ulicifolia)
Council provides a tool, on its Mountain Landscapes website, to help you choose native alternative plantings. Choose your village, soil, vegetation community and the purpose of your planting, and the tool will give you suggestions.
There are native nurseries in several Blue Mountains villages, including Glenbrook, Lawson and Katoomba. Please also ask at your favourite local nursery.
- Hand remove
- Remove flowers, fruit, pods or seeds
- Stem inject or frill
- Cut and paint
Grasp stem at ground level. Rock weed backwards and forwards to loosen roots, then pull out gently. Carefully tap the roots to dislodge attached soil. Replace disturbed soil and pat down.
- Leave weeds so that roots do not make contact with soil; on a rock, for instance. A small amount of debris may be hung in a tree or removed from the site.
- Vary the position of your body to avoid fatigue when removing plants by hand over extended periods.
Remove seeds, pods or fruit
Gently remove any seeds, pods or fruit and carefully place in a bag.
Note: Herbicides that may be used for this weed include Glyphosate.
Stem injection or frilling
At the base of the tree, drill holes at a 45° angle into the sapwood (just under the outer bark) at two finger space intervals around the entire base of the tree. Repeat this process below the lowest branch
As an alternative to drilling, make cuts into the sapwood with a chisel or axe. Fill each cut/hole with herbicide immediately. Repeat the process at 3 cm intervals around the tree.
Plants should be healthy and actively growing. Deciduous plants should be treated in spring and autumn when leaves are fully formed. For multi-stemmed plants, inject or chip below the lowest branch or treat each stem individually. Herbicide must be injected immediately before the plant cells close (within 30 seconds before translocation of herbicide ceases.)
Cut and paint
Useful for small to medium sized woody weeds up to 10 cm in diameter.
Make a horizontal cut as close to the ground as possible with secateurs or loppers, and immediately apply concentrated Glyphosate to the exposed stump surface. Do not allow the surface to get covered with soil.
Specific control tips for this weed
Because the seeds are bird spread, treat plants before they fruit. Bag and remove all pods. Seedlings and small plants are easily hand-pulled. Cut and paint or stem inject young plants. Stem inject large trees with herbicide.
For key points on these techniques:
Local Priority Weed
- The plant should be fully and continuously suppressed and destroyed.
- Plants under 4 metres in height should be fully and continuously suppressed and destroyed.
- The spread of this plant should be adequately contained to prevent spread impacting on priority assets. Weed notices will only be issued for these weeds under special circumstances.