Scotch Broom wiped out at Aussie Ark after 10 years

Success achieved via partnership with Scone Landcare NSW using gall mites

Aussie Ark is celebrating a major environmental victory with the complete eradication of the exotic Scotch Broom across its site, including the 400-hectare Barrington Tops Wildlife Sanctuary. This achievement marks the end of a nearly 10-year mission to restore native habitat in the Barrington’s and signals hope for broader landscape recovery.

Scotch Broom (Cytisus scoparius) is a highly invasive, noxious weed that was introduced as an ornamental garden plant to the World Heritage Listed Barrington Tops in the early 1900s. With its signature bright yellow flower, it has spread aggressively across the region including into National Parks. It’s one of the most serious environmental threats in the Barrington region.

In partnership with Scone Landcare, Aussie Ark first released English broom gall mites (Aceria genistae) in April 2016 as part of an ambitious biological control program. Today, thanks to this innovative approach, Scotch Broom has vanished from the Sanctuary, delivering what Managing Director Tim Faulkner calls an “ecological miracle.” He goes on to say, “These mites, tiny little insects, are proving to be environmental heroes, killing Scotch Broom and providing a natural control solution ongoing in the Australian landscape.”

“In 2016, alongside Scone Landcare, we took bold action to reclaim our Sanctuary from this devastating weed,” said Mr Faulkner. “Conventional methods, such as cutting down broom by hand, are like taking toothpicks to a swordfight. The incredible result with the gall mite proves that with the right strategy and conditions, we can win our war on weeds! We’re encouraging the National Parks & Wildlife Service and other land managers to adopt this approach for spring 2025.”

“The gall mites lie dormant through winter but come spring they’ll re-activate, making it the perfect time to harvest mites and expand releases into other affected areas.” Mr Faulkner concluded. “Aussie Ark has a surplus of mites to share…and spring is our time to strike!”

Scotch Broom (Cytisus scoparius) is one of the most damaging invasive weed species. It forms dense, impenetrable thickets that choke out native plants, devastate habitat for wildlife, and dramatically alter ecosystems. By fixing nitrogen in the soil, it makes conditions unsuitable for many native species to regenerate. Its presence increases the risk and intensity of bushfires, as it burns with extraordinary heat, causing long-term damage to native bushland. The seed bank can persist in soil for up to 100 years, making eradication notoriously difficult and costly.

The eradication of Scotch Broom at Aussie Ark opens the door to renewed biodiversity, with native flora and fauna quickly reclaiming, and thriving in, the landscape.

This outcome would not have been possible without the support of Scone Landcare. Their dedication in helping with the initial gall mite releases and ongoing monitoring set the foundation for success. The project highlights the vital role that local Landcare groups play in tackling invasive species and protecting native ecosystems.

“This is an outstanding example of what can be achieved when passionate organisations like Aussie Ark work hand-in-hand with local Landcare groups,” NSW Landcare Enabling Program Manager Jodie Lovell said.

“The eradication of Scotch Broom from such a significant Sanctuary is not just a local win. It’s a model of success that can be replicated across the state. Landcare NSW is proud of Scone Landcare playing such an important role in this long-term science-backed effort to restore native landscapes.”

Aussie Ark hopes this achievement will inspire wider adoption of biological control programs to combat Scotch Broom across Australia and create healthier, more resilient landscapes.