Imagine this: vibrant, cheerful gazanias, beloved by many for their sunny blooms, are actually waging war on Australia's farmlands and natural landscapes. This is the stark reality, and a growing chorus of farmers, environmentalists, and researchers are demanding a nationwide ban on their sale. But here's where it gets controversial... is it too late to stop the spread?
Gazanias, though pretty, are classified as environmental weeds in several Australian states, including Victoria, Queensland, Tasmania, and New South Wales (specifically Gazania rigens). South Australia has already taken action, banning their sale, but they continue to flourish in nurseries elsewhere.
These seemingly innocent flowers are not just taking over roadsides, native grasslands, and coastlines; they're also invading productive farmland. The consequences? Significant economic losses for farmers.
Take the case of Loxton farmer Robin Schaefer, whose fields, once fertile grounds for lentils and legumes, are now dominated by gazanias. "They just exploded," he says, emphasizing their aggressive nature. "Gazanias take over the environment, and nothing else will grow around the plants." Some farmers are facing even more severe infestations, with their paddocks completely overrun, rendering them useless for crop production.
And this is the part most people miss... the financial impact. Weeds and invasive species, including gazanias, cost Australia's agricultural sector an estimated $5 billion annually.
But why are these South African imports such a problem? Introduced to Australia in the 1950s and 1970s as low-maintenance garden plants, gazanias have spread rapidly across the continent. They've hitched rides on garden waste, cuttings, and through seed dispersal.
Berri Barmera Landcare project officer Andrew Walladge draws a parallel between gazanias and carp, highlighting their destructive habits. "They are a colourful cancer, very insidious, very quick-moving," he states, adding that they "suck the life out of our soils, and they're taking away natural resources."
The plant's seed dispersal is a major challenge, enabling them to colonize remote locations, such as the tops of sand hills and among native vegetation. According to Mr. Walladge, each flower head releases approximately 60 seeds, which are easily carried by wind and water, potentially traveling distances of 10 to 30 kilometers.
A recent study from La Trobe University revealed that gazanias are even more resilient than previously thought. They can thrive in almost any Australian environment, making them a significant threat to native grasslands and grain production.
Dr. Ali Bajwa, the lead researcher, explains that gazanias can adapt to the harsh Australian climate, making their management "extremely difficult." They outcompete native vegetation and crops for essential resources, such as nutrients, moisture, and light. Moreover, gazanias are inherently tolerant to many chemical herbicides, further complicating control efforts. Dr. Bajwa is currently involved in field trials to explore alternative chemical control options.
Here's a thought-provoking question: Could the widespread sale of gazanias be considered irresponsible, given their invasive nature?
According to a 2004 report, at least three-quarters of the weeds established in Australia originated from escaped garden plants. Imogen Ebsworth, from the Invasive Species Council, is urging the federal government to implement national regulations to prevent the sale of invasive garden plants. She warns against repeating the mistakes of the past, citing lantana and blackberry as examples of plants once sold as garden staples that are now among Australia's worst invasive weeds.
Ms. Ebsworth emphasizes that the vast majority of the 30,000+ introduced plant species in Australia haven't been assessed for their weed risk. She advocates for plant risk assessments and national regulation of garden plant sales, ensuring that consumers are informed about the environmental impact of their purchases. She believes that people shouldn't need a botany degree to understand what they're buying at nurseries.
Mr. Walladge, a former native plant nursery operator, calls the sale of gazanias "insanity."
However, the nursery sector's peak body, Greenlife Industry Australia (GIA), states that gazanias can still be legally grown and sold in most parts of Australia. The Department of Climate Change, Energy, the Environment and Water is currently developing a Threat Abatement Plan in collaboration with state and territory governments, which may include regulation.
So, what can gardeners plant instead?
Ms. Ebsworth recommends planting native species, such as everlasting daisies (Xerochrysum bracteatum), also known as paper daisies. These plants are well-suited to harsh conditions and support local birds, bees, and butterflies, making them an environmentally friendly alternative to gazanias.
What are your thoughts? Do you think a national ban on gazanias is necessary? Share your opinion in the comments below!
