Bush Heritage and the Dja Dja Wurrung enterprise DJANDAK are working together to control Wheel Cactus (Opuntia robusta) at Buckrabanyule Reserve in north-west Victoria. The reserve contains Victoria's largest known Wheel Cactus infestation. After five years of testing control methods, a 99% kill rate on mature plants has been achieved using foliar spraying, with more than half the infestation already treated.

Together with Dja Dja Wurrung enterprise DJANDAK, we’ve developed an effective way to control Wheel Cactus at Buckrabanyule Reserve on Dja Dja Wurrung Country in north-west Victoria, 270 km north-west of Melbourne.

Shana Nerenberg (DJANDAK Biodiversity Lead).

Buckrabanyule: A story of Country, Cactus & Combating Invasives

The reserve is a site of deep cultural significance for Dja Dja Wurrung Traditional Custodians. But sadly, a biosecurity risk – Wheel Cactus (Opuntia robusta) – also calls this special place home.

What is Wheel Cactus?

“It’s a really robust version of a prickly pear,” says Biodiversity Lead at DJANDAK Shana Nerenberg, who has been spearheading a 10-year strategy to combat the introduced species.

Listed as a weed of national significance, it covers most of the reserve and poses a broader threat to the region’s cultural, conservation and agricultural assets.

“Buckrabanyule is the heartland of the Wheel Cactus infestation for the whole of Victoria; we’re the seed supplier for the rest of the landscape.”

– Shana Nerenberg, Biodiversity Lead at DJANDAK

Wheel Cactus (Opuntia robusta) establishes and spreads quickly, with seeds dispersed in droppings by birds, foxes and other animals, as well as by machinery and vehicles.

It then rapidly transforms the function of a landscape, altering habitat for native fauna and outcompeting other plant species. Its nasty spikes also raise safety concerns for those working on and caring for Country.

Wheel Cactus control methods

When we first acquired the reserve in 2021 and began co-developing plans with DJANDAK and DJAARA (Dja Dja Wurrung Clans Aboriginal Corporation), controlling and suppressing the scale of the infestation at Buckrabanyule seemed insurmountable.

However, after five years of running experimental trials to test different control methods, we’ve found one that is most effective.

Foliar spraying

“The method is called foliar spraying, which means the whole cactus gets sprayed with a chemical, touching every single part of the plant,” explains Shana. “We’ve had a really good kill rate. After one spray, 99% of the adult plants are dying off within a couple of months.”

After a year, we repeat and re-treat the area to eliminate any persistent seedlings, before moving on to the next patch of adult cactus.

Thanks to Stone’s Forestry Contracting, who are carrying out the bulk of the arduous in-field work, more than 50% of the cactus has been treated at Buckrabanyule.

A hill once cloaked in mossy green pads is now fading to brown, and in the future will be restored with native grasses and plants.

Sharing our knowledge

The process has been a learning journey, and we’re continuing to test the method and the herbicide application rate, particularly in lower-density areas, to ensure our practice is as safe and efficient as possible. This includes research into the species’ response to burning and cultural fire practices.

Fully controlling the cactus will be a collaborative effort, and to do so we need to bring others along with us who are also facing incursions of the weed on neighbouring properties.

“It’s important we share our knowledge, through community working days, talking to other local environment groups and sharing what’s working and what’s not working,” says Dan Nugent, Buckrabanyule Reserve Manager for Bush Heritage.

In addition to involving those close to Buckrabanyule, we’ve taken the methodology to a statewide audience.

Late last year, Shana and Bam Lees, Aboriginal Partnerships Manager for Bush Heritage, jointly presented our success controlling the noxious weed as a keynote address at the Victorian Weeds Conference, where it gained statewide recognition.

“We hope our lessons will inform efforts across Victoria to turn the tide on Wheel Cactus, and that future control at Buckrabanyule is as easy as an annual walk-through to spray any lingering plants – freeing up time for our communities and staff to address other threats to the landscape,” says Dan.

We’re extremely proud of our ongoing partnership with DJAARA and DJANDAK, Wurreka Galkangu, which allows us to find new ways to tackle even the most entrenched environmental challenges and bring about strong, culturally informed outcomes for Country and people.

We thank and gratefully acknowledge DJAARA for their partnership and the Helen Macpherson Smith Trust for their generous support of Wurreka Galkangu.

The video (above) about our Wheel Cactus control and a community field day, were supported by the Victorian Government through the Partnerships

Against Pests program, and the control of Wheel Cactus was also support by the Victorian Government through the Protecting Biodiversity program.