In the mid-nineteenth century, Queenslanders were already observing that the plant was dangerous. Cattle, sheep and goats would eat the poisonous plant and then die if not treated. But not all farmers were wary of lantana. “Some of the farmers in Queensland found the plant useful, especially in the banana growing regions,” says Janine, “not only as a fertiliser, because it contains potash, but also because it keeps other weeds down.”
This was why some farmers actually introduced and encouraged the plant to grow on their property. “They thought they were better off dealing with one type of weed rather than with many, as lantana is effective at killing other plants around it,” Janine says.
What is a weed after all?
Looking from today’s perspective, in a country with some of the strictest biosecurity laws in the world, it seems surprising that people would introduce such a dangerous weed in the first place. The biggest issue was that back in the nineteenth century, there was no legal definition of a weed, yet. In addition, the European settlers thought that almost everything that was coming into Australia from overseas was superior, including plants and animals.
It all started some time around 1841. That is the date of the earliest record that Janine discovered. “I found an article in the South Australian Journal , by a nursery man called John Bailey who came from London,” Janine says. “Then I found another reference to lantana in Camden, Sydney, by John MacArthur. MacArthur was the largest sheep farmer in Australia at the time and he grew the plant in his nursery in Camden.”
‘Improving’ the Australian landscape
Apart from commercial nurseries bringing plants into Australia to make a profit, or other people’s efforts to ‘improve’ the landscape, says Janine, “European settlers also exchanged plants like lantana because they liked the flowers. But once lantana had become established in Queensland’s tropical environment, it simply exploded.”
Even if farmers complained about the weed in the early years of its arrival, the colonial government was slow to act and there was little money available to support its eradication. “The government’s priority was getting the economy going. In Queensland we didn't have gold or other mineral discoveries at the time. That only came later,” Janine says. “The priority around the mid-nineteenth century was on sheep, cattle and agriculture, such as producing exotic fruits.”
Disunity among Queensland’s farmers
Janine adds that Queensland is very decentralised, with the main seat of government in Brisbane while North Queensland towns a long journey away. “They had these divisional boards which oversaw local government areas. You could have one divisional board saying lantana is a massive problem,” Janine says, “and then a neighbouring divisional board might not think it’s such a big issue, as there could have been some benefits for the local farmers.”
A lack of cooperation across Queensland helped lantana to spread. “You can’t control it if everybody is not doing the same thing,” Janine says. “The politicians in Brisbane also argued over how to define a weed for two years.”
Lantana – out of control
Lantana has been targeted for biological control since 1914. By that time, lantana had spread around the entire east coast of Australia making it difficult, if not impossible, to eradicate the weed by one single means. “Carried by birds and floodwaters, the plants are very productive. They produce 12,000 seeds from one single plant," Janine says.
Since the 1910s, several weed killing substances having been introduced and experimented with. So far none have been successful due to lantana being so widespread. "You might be able to control lantana in some places, but other places might be more difficult,” Janine says. “For example, governments can’t control what people do on their private lands. If someone has a plot somewhere with lantana on it and it’s just left to grow, well, then there’s not much you can do about that.”
Lantana and cane toads
When asked if lantana can be compared to cane toads that have also overrun Australia, Janine says, “we can’t really compare animals and plants. Plants move via birds and waterways. But a plant like lantana needs humans to spread it. Weeds like lantana follow human settlement.”
Janine says animals, on the other hand, are very different. “Animals are mobile. They can go where people don’t go. I’m pretty sure cane toads also exist where humans don’t.”