A call to action is ringing out across Australia, demanding attention and sparking controversy. It's time to talk about the bright and beautiful gazanias, a popular garden plant with a dark side. Farmers, environmentalists, and researchers are uniting to sound the alarm, urging a national ban on the sale of this invasive weed. But here's where it gets controversial: these vibrant flowers, native to South Africa, have become a serious threat to Australia's agriculture and ecosystems.
Gazanias have already been recognized as an environmental weed in several states, including Victoria, Queensland, Tasmania, and New South Wales. Their impact is far-reaching, overrunning roadsides, native grasslands, and coastlines, and even invading productive farmland in South Australia, Victoria, and Western Australia. The consequences are severe, rendering farmland unviable and causing significant economic losses.
Take the case of Loxton farmer Robin Schaefer. Where he once grew lentils and other legumes, gazanias have taken over, choking out any other growth. "They just exploded," Mr. Schaefer said. "Gazanias take over the environment, and nothing else will grow around them."
The problem extends beyond individual farms. Weeds and invasive species, including gazanias, are estimated to cost Australia's agriculture sector a staggering $5 billion annually. And this is the part most people miss: these garden escapees are not just a financial burden but a threat to our native biodiversity.
Gazanias were first imported to Australia in the 1950s and 1970s as low-maintenance garden plants. Since then, they've spread across the continent through garden waste, cuttings, and seed dispersal. Andrew Walladge, a project officer at Berri Barmera Landcare, compares their destructive habits to carp in Australian river systems. "They are a colourful cancer, very insidious, very quick-moving," he warns.
The plant's seed dispersal is a major challenge, allowing gazanias to spread into remote areas and native vegetation. Each flower head releases around 60 seeds, which are windborne and can travel great distances. With strong winds, they can easily cover 10 to 30 kilometers.
A recent study by Dr. Ali Bajwa's weed science group at La Trobe University found that gazanias are more resilient than previously thought. Their ability to thrive in almost any Australian environment makes them one of the biggest threats to native grasslands and grain production.
"They can choke a lot of the native vegetation and crops in production systems, outcompete them for resources such as nutrients, moisture, and light," Dr. Bajwa said. "Gazanias are inherently tolerant to a lot of different chemical herbicides, and that's why we can't really control them."
Dr. Bajwa is part of a Grains Research and Development Corporation project investigating potential chemical control options for gazania. But the question remains: why are we still selling this invasive species?
According to a 2004 report by biosecurity strategist John Virtue, at least three-quarters of weeds established in Australia have come from escaped garden plants. Imogen Ebsworth, engagement director at the Invasive Species Council, urges the federal government to introduce national regulation to stop the sale of invasive garden plants like gazanias.
"We've got over 30,000 introduced plant species in Australia, and unfortunately, the vast majority have never been assessed for their weed risk," Ms. Ebsworth said. She calls for plant risk assessments and national regulation of garden plant sales to ensure people are buying environmentally safe plants.
Mr. Walladge, who previously ran a native plant nursery, describes the sale of gazanias as "insanity." "Selling effectively a noxious weed is just bonkers," he said.
While Greenlife Industry Australia acknowledges that gazanias are not nationally prohibited, several jurisdictions discourage their use due to their invasive potential, and future restrictions are under consideration.
The Australian government is developing a Threat Abatement Plan in collaboration with state and territory governments, which may include regulation. However, given the complexity of managing the threat from escaped garden and pond weeds, the process is expected to take several months.
So, what can we do as gardeners? Imogen Ebsworth recommends planting native species instead of gazanias. Everlasting daisies (Xerochrysum bracteatum), also known as paper daisies, are a great native alternative.
"They are just as adapted to harsh conditions as gazanias are, and you're planting something that's native to your area," she said. "That's going to help the birds, bees, and butterflies in your space, and you're not going to be planting an invasive plant."
It's time to make a change and protect our environment. Will you join the movement to ban the sale of invasive gazanias? We'd love to hear your thoughts in the comments below.
