(Also known as Mt Morgan Wattle)
Type of weed: Woody weed
Flower colour(s): Yellow
Priority Weed Local Priority Weed. (See more weeds of the Local Priority Weed class.)
An upright, spreading shrub or small tree usually growing 2-6m tall. The bark on the main trunk is grey or greyish-brown. Younger branches are round, with a dense covering of hairs. They are also conspicuously whitish or bluish-green.
The ‘leaves’ are actually flattened and widened leaf stalks called phyllodes. The phyllodes are alternately arranged along the stems, oval in shape and usually silvery-grey to bluish-green.
The small bright yellow or golden-yellow flowers are fluffy and densely arranged into small clusters containing 15–30 flowers. The plant can flower all year.
The fruit is a long, flattened pod with a short stalk and prominent margins. Pods are velvety hairy, bluish-green or silvery-grey in colour. Seed is long-lived and germinates quickly after fire and other disturbances.
Mt Morgan Wattle is a native plant from Queensland but has become invasive outside its original range. It can be mistaken for local wattles and is often planted in gardens.
Seed is dispersed by birds, ants, machinery and by in dumped garden waste. They are probably also spread by wind and water.
Impact on bushland
Mt Morgan wattle moves into intact bushland displacing local wattles. Some infestations are scattered. Where it forms dense stands, it shades out other native plants. It also fixes nitrogen in the soil, making it unsuitable for the germination of many local native plants.
Local native wattles:
- 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
- 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.
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
- Small to medium seedlings can be hand pulled.
- Cut and paint saplings with herbicide.
- Drill and 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.