Daniel Forwood
WHEEL cactus has infested several areas of Sunraysia as its continues its march across northern Victoria.
The latest Landcare maps show an alarming solid red patch starting near Kerang and spreading north-west along the Murray River.
Given weeds such as serrated tussock and blackberry already cost the Victorian economy $900 million a year, significant investment is required to stop the spread of wheel cactus.
Recognising the magnitude of this cactus-borne catastrophe, a team of dedicated local volunteers from surrounding Landcare groups and landholders formed the Tarrangower Cactus Control Group in 2005 with one primary target – wheel cactus.
Group president Lee Mead leads the charge of the Froggatt Award-winning organisation, protecting Australian native plants, animals and the natural environment from the incursion of dangerous new invasive species.
Wheel cactus, which is plaguing the northern and central Victorian landscape, is a rapidly spreading, wheel-shaped reminder of Australia’s prickly past.
“There’s just as much wheel cactus as there is when we started. It grows just as fast as it’s killed,” Lee Mead says.
Ms Mead and the Cactus Warriors work passionately to raise the profile of wheel cactus, increase awareness and educate farmers.
Many property owners are actively controlling wheel cactus, but their hands are tied when it comes to the apathetic or absentee property owners and securing Victorian Government resources as wheel cactus is not considered a priority weed.
“People don’t think cacti are a problem,” Ms Mead says. “Wheel cactus won’t stop spreading.”
An ornamental, drought-resistant shrub turned escapee garden plant; wheel cactus (Opuntia robusta) is named after its peculiar spherical shape.
Once an oddly placed fixture in the Victorian landscape, wheel cactus has undergone plague-like spread in northern and central Victoria, akin to the other 27 opuntia species across Australia.
It is native and endemic to central and northern Mexico.
Each species has its own unique biological features, growth patterns and response to chemical treatments.
This has firmly etched their place as weeds of national significance, an infamous accolade awarded to 32 weeds based on their invasiveness, potential for spread and environmental, social, and economic impacts.
In Victoria, several catchment management authority boundaries aim to prevent further spread of wheel cactus.
The Australian climate presents ideal conditions for wheel cactus to naturalise and spread into Victoria, South Australia, NSW and Queensland.
With no natural predators, no competing cactus species native to Australia and a tendency to grow on top of inaccessible rocky granite hills, the weed has established itself in regions of Victoria during the past 50 years.
With the continued threat of infestations at some sites merging, now is the time to act to mitigate the development of a core wheel cactus seedbank.
– Courtesy of the Victorian Farmers Federation
