Parkinsonia is a spiny shrub or small tree with yellow flowers. It forms dense, impenetrable thickets especially around watercourses, streams and water bodies.
Parkinsonia forms dense, spiny thickets that restrict access to land and waterways. It also:
Parkinsonia is a single or multi-stemmed shrub or small tree up to 8 m tall.
The leaves are made up of a flat green leaf stalk up to 30 cm long and 2–3 mm wide. Along the stalk are 10–40 pairs of small leaflets that are:
There are several similar looking prickly bushes. The main difference is that Parkinsonia is the only species that has a flattened leaf stalk. The other species all have fern-like leaves with larger leaflets. Similar plants include:
There have been isolated infestations in and around Broken Hill, Walgett, Bourke and the far north-western corner of NSW. In 2020 it was found near Brewarrina and these plants are under an eradication program. Parkinsonia could invade most of western NSW particularly along riverine areas. It could also invade the northern and central coastal areas.
In the late 1800s, it was brought to Australia as a shade and ornamental tree. It has naturalised throughout most of northern Australia.
Parkinsonia is native to the Americas and the Caribbean. It is a weed in Africa, the Mediterranean, south-western Asia, India and the Pacific Islands.
Parkinsonia grows in arid to wet-dry tropical climates with rainfall from 250 to 1400 mm/year.
It is a hardy plant and tolerates:
Wetlands and floodplains are very susceptible to invasion. Parkinsonia also grows well on open grasslands and rangelands.
Parkinsonia plants usually produce about 5000 seeds/year. Seed production starts when trees are 2 or 3 years old.
Seeds have a hard, thick coat and can remain dormant in or on the soil surface. In most locations, seeds are only viable for up to one year. Though some have been recorded viable after being dormant for 4 years. Fires can cause germination. Mass germination occurs in wet and warm to hot conditions.
Many seeds fall close to the parent plant. However, seeds are spread by:
CRC for Australian Weed Management (2003) Weed Management Guide: Parkinsonia – Parkinsonia aculeata.
Hosking, J.R., Sainty, G.R., Jacobs, S.W.L., & Dellow, L.L. (in prep). The Australian WeedBOOK.
Parsons, W.T., & Cuthbertson, E. G. (2001). Noxious weeds of Australia. CSIRO publishing.
PlantNET (The NSW Plant Information Network System). Royal Botanic Gardens and Domain Trust, Sydney. Retrieved: 20 January 2021 from https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Parkinsonia~aculeata
Queensland Government. (2020). Identification of prickle bushes. Retrieved 13 August 2020 from: https://www.daf.qld.gov.au/__data/assets/pdf_file/0006/72195/IPA-Identification-Prickle-Bushes-PP40.pdf
van Klinken, R. D., Campbell, S. D., Heard, T. A., McKenzie, J., & March, N. (2009). The Biology of Australian Weeds: 54.'Parkinsonia aculeata'L. Plant Protection Quarterly, 24(3), 100.
If you suspect you have found Parkinsonia contact your local council weeds officer. They will assist with identification, removal and eradication.
A range of control options are available for Parkinsonia. A suitable control program should be tailored to suit the landscape and size of the infestation. Successful weed control relies on follow up after the initial efforts. This means looking for and killing regrowth or new seedlings. Using a combination of control methods is usually more successful.
To tackle Parkinsonia:
Avoid moving soil from infested areas. Clean machinery after use in areas with Parkinsonia. Hold stock in a quarantine paddock before moving them from areas with Parkinsonia to uninfested areas.
Hand pull small Parkinsonia plants or grub them out with a mattock.
When: At the start of the dry season when the infestation first becomes accessible to heavy machinery but there is still moisture in the soil.
Follow-up: With chemical control, fire or careful machine operations to treat survivors, regrowth and new seedlings.
Mechanical control of large infestations may be more cost-effective than chemical control, especially on flat even ground. Parkinsonia can be bulldozed, stick-raked, blade ploughed or chain pulled. Remove the roots to about 200 mm deep to prevent them from reshooting with multiple stems. Multi-stemmed plants can be more difficult to remove than the original plants.
Permits may be required if native species could be affected by the Parkinsonia control effort. Machinery is not recommended for controlling Parkinsonia along river banks as this may cause erosion and damage to non-target species.
Where practical sow perennial pastures to prevent Parkinsonia seedlings from establishing.
Spot applications to the soil are best when the plants are actively growing and the soil is moist. Spear applicators are best if there is leaf litter or pasture around the target plants.
Basal barking can be used for plants with stems up to 5 cm in diameter at the base. Liberally spray the bark all the way around the stem from ground level to 30 cm high. Wet thoroughly to the point of runoff. Apply to dry stems as wet stems can repel the mixture.
Best results are achieved when soil is moist and plants are actively growing.
Cut trunks or stems less than 15 cm above the ground. Apply herbicide to the cut and the sides of the stump immediately.
See Using herbicides for more information.
Hexazinone 250 g/L
(Velpar® L)
Rate: 4 mL per spot
Comments: One spot per bush up to 5 m tall.
Withholding period: No stated withholding period.
Herbicide group: 5 (previously group C), Inhibition of photosynthesis at photosystem II - D1 Serine 264 binders (and other nonhistidine binders) (PS II Serine 264 inhibitors)
Resistance risk: Moderate
Hexazinone 250 g/L
(Velpar® L)
Rate: 1 mL per spot
Comments: One spot per bush up to 1 m tall. Do not use near desirable plants.
Withholding period: No stated withholding period.
Herbicide group: 5 (previously group C), Inhibition of photosynthesis at photosystem II - D1 Serine 264 binders (and other nonhistidine binders) (PS II Serine 264 inhibitors)
Resistance risk: Moderate
Picloram 44.7 g/L + Aminopyralid 4.47 g/L
(Vigilant II ®)
Rate: Undiluted
Comments: Cut stump/stem injection application. Apply a 3–5 mm layer of gel for stems less than 20 mm. Apply 5 mm layer on stems above 20 mm .
Withholding period: Nil.
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate
Triclopyr 240 g/L + Picloram 120 g/L
(Access™ )
Rate: 1.0 L in 60 L of diesel (or biodiesel such as Biosafe).
Comments: Basal bark application for plants with stems up to 5 cm diameter at the base. Cut stump application can be used for plants with stems up to and in excess of 5 cm diameter at the base. See label for information about biodiesel.
Withholding period: Nil
Herbicide group: 4 (previously group I), Disruptors of plant cell growth (Auxin mimics)
Resistance risk: Moderate
The content provided here is for information purposes only and is taken from the Biosecurity Act 2015 and its subordinate legislation, and the Regional Strategic Weed Management Plans (published by each Local Land Services region in NSW). It describes the state and regional priorities for weeds in New South Wales, Australia.
Area | Duty |
---|---|
All of NSW | General Biosecurity Duty All pest plants are regulated with a general biosecurity duty to prevent, eliminate or minimise any biosecurity risk they may pose. Any person who deals with any plant, who knows (or ought to know) of any biosecurity risk, has a duty to ensure the risk is prevented, eliminated or minimised, so far as is reasonably practicable. |
All of NSW |
Prohibition on certain dealings
Must not be imported into the state, sold, bartered, exchanged or offered for sale. |
All of NSW
Parkinsonia Control Zone: Whole of NSW |
Control Order
Parkinsonia Control Zone (Whole of NSW): Owners and occupiers of land on which there is parkinsonia must notify the local control authority of new infestations; immediately destroy the plants; ensure subsequent generations are destroyed; and ensure the land is kept free of the plant. A person who deals with a carrier of parkinsonia must ensure the plant (and any seed and propagules) is not moved from the land; and immediately notify the local control authority of the presence of the plant. |
Reviewed 2022