A highly invasive plant dubbed the “cancer of the plant world” that has destroyed large tracts of land in the southeastern United States has made its way to Canada.
The kudzu vine (Pueraria Montana) was spotted in July on a south-facing slope overlooking Lake Erie near Leamington, Ontario, a farming community about 35 miles southeast of Detroit, MI.
While the patch of kudzu is still relatively small at about 360 feet wide and 100 feet deep, the Ontario Invasive Plant Council (OIPC) has said it’s imperative to “take immediate action in Ontario to stop kudzu in its tracks.”
According to the OIPC, kudzu grows at a rate of one foot per day and blankets everything in its path—fences, trees, crops, and even buildings. The thick, leafy vine climbs hydro poles and transmission wires, which ultimately collapse under its weight. Trees are either broken by its weight or killed by the lack of light.
“[Kudzu] can completely take over a patch of landscape—it becomes a desert in a sense, destroying biodiversity,” said Dr. Rowan Sage, an ecology professor at the University of Toronto, who began studying the plant 20 years ago.
“It shows extremely vigorous growth. It has vines that can wrap around themselves and self-support each other, so it can overtop much of the vegetation and get it out of the ecosystem.”
Native to East Asia, kudzu was first brought to the U.S. from Japan for use as an ornamental plant at the Philadelphia Centennial Exposition in 1876. It was later used for erosion control and promoted as a forage crop.
Eventually it took over large swathes of land in the southern U.S. and has continued to spread northward, despite efforts to stop it. Attempting to keep the so-called vine that ate the south at bay costs the U.S. agriculture industry $500 million annually, according to news reports.
Sage said kudzu has spread to a number of places besides North America, including the deforested section of the Central Amazon Basin in Brazil. It is unknown when the plant took root in Canada.
While Kudzu produces seeds, it normally spreads through its root system with each root ball generating as many as 30 vines.
“If you get a kudzu stem or root it’ll just take off unless it’s killed by severe winter cold or drought,” Sage said, adding that kudzu’s root tissues can be killed at minus four degrees Fahrenheit.
Measures to control the spread of kudzu include hand cutting, mowing, controlled burns and herbicides. Grazing animals, such as goats and pigs have also been effective at containing the spread of the vine over the long term, according to the IOPC.
“When you find it, you have to eradicate it right away,” said Sage. “Once it’s established, you need to be rigid about it. It’s easy to remove, but it’s scattered about, and it’s gradually regenerating, so it’s expensive to get rid of.”
Kudzu, which thrives in open sunny areas, can also carry soybean rust, a fungus that can spread to soybeans and reduce yields. Soybeans are one of southern Ontario’s main crops.
The patch of kudzu in Ontario is being observed and studied, said Sage, and will be eliminated later in the fall with funds from the federal and Ontario governments.
Other invasive plants that have made their way into Canada from Asia include Japanese bamboo and Eurasian water milfoil. Many invasive plants have been introduced from Europe over the years, including loosestrife, a garden ornamental plant that has overrun wetlands throughout eastern North America, pushing out native species.