In the vast and varied landscapes of Australia, where the natural beauty is as renowned as the wildlife, a silent invader is causing chaos and concern among property owners and farmers alike. This isn’t a creature from the Outback, but a plant with a sting in its tale – the harrisia cactus. This toxic species has been identified as Queensland’s most costly weed since 1960 and is now a painful, deadly threat that’s invading the Aussie landscape with alarming speed.
The harrisia cactus, originally introduced to Queensland as an ornamental plant in the 1800s, has become a symbol of the unintended consequences that can arise from importing foreign species. Its aggressive spread, particularly across the state’s northeast and in northern New South Wales, is a stark reminder of the delicate balance within ecosystems and the havoc that can ensue when that balance is disrupted.
Landowners in the country’s north are sounding the alarm, urging governments to intensify their control efforts against one of Australia’s most invasive plant species. The impact on the agriculture sector is profound, with dense thickets of the cactus reducing grazing land for livestock and, in some tragic cases, leading to the euthanasia of animals that have been injured by its spines.
The story of Ken Stower, a Queensland man who owns a 1,400-hectare property at Captains Mountain, is a heart-wrenching example of the cactus’s destructive power. After his prized $20,000 bull trod on the cactus, Stower was forced to make the difficult decision to put the animal down. ‘We had to euthanise him — it was difficult financially as well as mentally,’ Stower shared with the ABC. The spines of the harrisia cactus are so robust that they can penetrate a four-wheel drive tyre, making them a lethal hazard for animals.
Sally McKeering, another Queenslander who works on her cattle property near Alpha, knows the pain of the cactus all too well. After falling into the plant, she required surgery to remove the deeply embedded needles from her hand, an injury that occurred despite wearing gloves. McKeering also witnessed the toll on her livestock, with horses being crippled by the cactus’s spines.
Control efforts, including mechanical removal, chemical treatments, and biological control with a mealybug that specifically targets the weed, have been implemented, but the challenge remains daunting and expensive. The mealybug, while effective on some farms, requires manual transportation, adding to the logistical hurdles faced by those battling the spread.
The Invasive Species Council has been vocal in its plea for a national plan to address escaped weedy garden plants and other introduced threats, which collectively cost the Australian agriculture industry over $4 billion annually to manage. Kathleen Herbert, the Council’s Campaign Coordinator and bush regenerator, has pointed out that self-regulation within the industry is failing, and government intervention appears to be the only viable solution.
Herbert’s concerns extend to the hundreds of Australian nurseries, including major retailers like Bunnings, that continue to stock plants and seedlings classified as highly invasive. These sales are legal, but they contribute to the problem, and Herbert is among those calling for legislative changes.
Have you encountered the harrisia cactus or other invasive species on your property? What measures have you taken to combat them? Share your experiences and insights in the comments below, and let’s discuss how we can protect our beautiful Australian countryside together.
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