Four years ago, Saanich resident Terry Smollett picked up a copy of the Saanich News and sat down to read. Turning through the pages, he made a perplexing discovery when he came across a photo of a plant all too familiar – one that was sprawling across his own backyard.
The article revealed that the lush broad-leafed plant, producing bright orange-red, berry-laden cobs, was actually a non-native weed considered to be both toxic and “highly” invasive.
“I had some in my garden and I didn't realize it was a noxious weed,” he said.
Originally introduced to North America from Europe for ornamental purposes, the Italian arum (arum italicum) may look pretty, but it can have disastrous impacts, warns the Capital Regional District (CRD).
Stout and tenacious, it thrives in a wide range of environments, from closed to open canopy, in variable soil conditions, and is drought-tolerant once established.
Its typical habitat includes gardens, roadsides, and natural areas, including forests, riparian areas and wetlands. Found throughout the south Island and the Lower Mainland, the Italian arum appears to be spreading, according to the CRD.
Because this species can tolerate cold temperatures, it is likely capable of establishing in most regions of B.C.
Said to be able to “cause severe skin irritation, illness, or death,” the CRD labelled the plant as highly toxic to people and animals. Yet, what makes this plant so problematic lies in its ability to spread like wildfire.
“It's very aggressive and it's very hard to get rid of,” said Smollett, who has spent the past years trying to wrestle the plant out of his yard.
“The first year, I just pulled them all out and put them in the garbage. Since then, any part of the plant that was left behind has grown.”
Ken Marr, a botanist and Smollett’s neighbour, said the threat of the invasive plant stems from its ability to reproduce quickly and strong-arm other (native) plants out of its way.
Capable of spreading through its seeds – often dispersed by birds – and its underground root system, Italian arum quickly forms a dense ground cover, blocking sunlight from reaching lower-lying plants.
Having already observed the non-native plant across the region, the botanist said the best way to deal with it is to act swiftly and kill the plant at its roots.
“The ideal thing is to remove it as soon as it appears, and hopefully it doesn't spread to new areas,” Marr said. “You would need to dig it up and get every last bit of it out of the ground.”
But to Smollett’s dismay, the invasive plant has already begun plaguing his neighbourhood, with colonies appearing in his neighbour’s backyard and on district-owned land.
Concerned that some neighbours are unaware of the plant’s threat and others unable to act due to age or health, Smollett fears a full-fledged invasion of the alien weed could wreak havoc in the neighbourhood.
In a written statement, Saanich reported first being aware of Italian arum’s presence about five years ago, following notices from the province.
The district currently manages 16 affected sites, noting that herbicide treatments at some locations “have been met with poor success.” As a result, crews are now dispatched to fully dig up the plant. Saanich confirmed that the site mentioned by Smollett was “treated” last week.
Although the Italian arum is one of about 30 invasive plants managed by the municipality, it’s not considered to be a top priority according to provincial and regional lists. However, the district mentioned taking its “potential spread seriously.”
“Considering how many invasive species we manage, using several priority invasive species lists, the work we are doing to manage Italian arum on public lands is quite significant,” added the statement. “We visit and treat every site that we are made aware of.”
If residents spot Italian arum on their property, the CRD urges residents to act quickly and carefully.
Citizens are advised to learn how to identify the plant and report sightings for confirmation and guidance. Small patches can be removed by digging out the entire plant, including the root system, while wearing gloves, and disposing of berries early. To prevent further spread, clean shoes, tools, pets and equipment after leaving affected areas.
After removal, replant with native or non-invasive species and monitor the site regularly for several years, as seeds and tubers can persist in the soil.
All plant material and attached soil should be bagged, labelled “invasive species,” and taken to the Hartland Landfill. The plant should never be composted.
Residents can report invasive species by calling 1-888-933-3722 (1-888-WEEDSBC) or online through the B.C. government’s website at shorturl.at/6z0mw.
More information on invasive species in Greater Victoria can be found on the Capital Regional District’s website, crd.bc.ca.
