Victorian Landcare Magazine - Spring 2025, Issue 90
At the turn of the 21st Century, concern was growing about the increasing number of cactus infestations around the district of Maldon, particularly wheel cactus (Opuntia robusta).
Not only were these plants spreading across private agricultural land, but they were also invading the Maldon Historic Reserve, treasured for its abundant natural and cultural heritage assets.
Local property owners, Landcare groups and Parks Victoria staff got talking and formed a sub-committee, consisting of Ian Grenda, Barrie McKnight, the late Wendy French and Noel Muller. In mid-2005 this committee successfully won a Victorian Government grant of $30,000, which was the impetus to establish the Tarrangower Cactus Control Group and “wage war on wheel cactus”.
The key objectives of the new group were to raise awareness of this species and the threats it posed, and to work out the most effective way to destroy it.
Community awareness activities focused on engaging with local landowners and giving them a helping hand to start treating their infestations. The group also partnered with Parks Victoria to help treat the many infestations within the spectacular Maldon Historic Reserve.
A native of Mexico, wheel cactus was declared a noxious weed in Victoria in 1963 and is listed as a weed of national significance. It can regenerate from pieces of the fleshy round lobe and its dark magenta fruit contain hundreds of seeds which are long lived – surviving for up to 20 years – and spread by birds, animals and water.
Volunteers experimented with how best to kill the plant, testing different techniques, including burning, digging, injecting and spraying. They found direct injection of herbicides, such as glyphosate and daconate, into the lobes proved most effective on mature plants.
Above: Tarrangower Cactus Control Group volunteers ready for a community field day in 2013. Many hundreds of community members have been involved over the years.
The group’s first community field day was held in October 2005 and became a monthly event for many years. Field days held on private properties or within the Maldon Historic Reserve were widely advertised and everyone in the community was welcomed. This attracted many urban volunteers as well as landowners, who formed a large team of cactus warriors to help attack infestations.
Providing free incentives to encourage landowners to control their wheel cactus has been a constant focus. Many grants have been secured for injecting and digging equipment, herbicide and the disposal of dug plants. Our volunteers have taken part in a variety of awareness and educational activities, such as information brochures, print, television and digital media releases, community events, information stalls, workshops, t-shirts, windcheaters, mugs and pens. Fundraising activities have also contributed to supplying equipment for our volunteers, such as a tailor-made trailer, barbecue and tables.
Networking with other environmental volunteer groups has always been important and members have taken part in many workshops and conferences, both within Victoria and interstate.
Funding has been secured from many different grant sources. Major projects completed during the past 10 years include distribution mapping of wheel cactus within Victoria, producing farm fence signs and shire-specific weed control brochures, introducing the biological control insect, cochineal (Dactylopius opuntiae), and creating individual, long-term management plans for private property owners.
Our dedicated volunteers have hosted many different work crews such as drought-relief and green army, secondary and tertiary student field days, and scout projects, all increasing awareness of environmental weeds amongst our neighbours and younger generations.
The Cactus Warriors are very proud of the enormous amount of work achieved by hundreds of volunteers over the past 20 years. We believe participating in community events on a regular basis over many years
has led to an extremely high level of awareness and knowledge about wheel cactus within our local community. We ‘guesstimate’ 70 per cent of local landowners now regularly control their wheel cactus plants, which is a never-ending chore due to the enormous seedbank and continuous re-infestation from non-compliant and absentee property owners.
The Maldon Historic Reserve now has significantly less wheel cactus, contributing to the preservation of our regional native flora and fauna. Plus, our volunteers have been recognised for their exceptional efforts by being awarded the Landcare Community Group Award at the 2017 Victorian Landcare Awards and the national Froggatt Award in 2019.
After about 13 years of regular community field days on private properties we felt our efforts were becoming counterproductive. Some landowners expected our team of volunteers to return to treat their infestations, and we were often asked to provide extra free herbicide. We decided to reduce the frequency of field days.
We also concluded that some landowners will never take advice from community volunteers, and we needed to conserve our energy by being more selective with the incentives we offer, so we have redirected our energies towards education and advocating to government agencies for greater engagement and compliance.
Above: Cactus warriors Cheryl Kane (from left), Steve Templeton and Bridie O’Rielly operate an information stall at the Maldon-Barringhup Agricultural Show.
Despite 20 years of relentless work, there are no fewer wheel cactus infestations around Maldon and, sadly, they have spread further in all directions. Our group now concentrates on organising smaller events, working bees and encouraging neighbouring landowners to work together. We invite new landowners to contact us for help and are happy to run a field day on their property to provide knowledge and motivation. We continue to encourage volunteers and landowners to participate by providing free loans of equipment and servicing broken injecting kits. We also continue to work with Parks Victoria in the Maldon Historic Reserve.
However, to remain sane, we must frequently remind each other of the millions of wheel cactus plants we have destroyed during the past 20 years and imagine what our wonderful natural landscapes would look like if we hadn’t. Our tenacious Cactus Warrior volunteers will celebrate 20 years of dedicated work later this year!
Funding bodies have included Mount Alexander Shire Council, Victorian Government Landcare Program, Australian Government and the Wettenhall Environment Trust.
Leeanne Mead is President of Tarrangower Cactus Control Group.
For more information, email info@cactuswarriors.org.