Invasives for sale

Many species of invasive plants are for sale to local gardeners. But species like knotweed can cause immense environmental damage.

  • Aug. 26, 2015 10:00 a.m.
A species like Japanese Knotweed can completely take over a property

A species like Japanese Knotweed can completely take over a property

Barry Coulter

It may strike one as surreal, but in the midst of an on-going awareness campaign about invasive species and an on-going battle against them, some of these species are for sale to gardeners in the East Kootenay.

Biologist Cathy Conroy, the Terrestrial Invasive Species Co-ordinator with the East Kootenay Invasive Plant Council (EKPIC), is setting out to bring light to this situation for both gardeners and horticulture retailers. She said the fact that some invasive species capable of causing harm are for sale here is largely to due a lack of awareness and a lack of regulation in the horticulture industry.

Baby’s breath, for example, is not listed as a “noxious weed,” which is the legal government designation for plants officially considered the enemy. However, just because a plant is not listed as noxious doesn’t mean it’s not invasive — a plant brought from somewhere else either intentionally or unintentionally — and capable of causing great harm to the environment.

Baby’s breath outcompetes natural grasses and will quickly spread over grasslands — a key East Kootenay ecosystem. “One per cent of B.C. is grasslands,” Conroy said, “and it’s one of the most endangered B.C. ecosystems.”

Baby’s breath has an enormous taproot, almost turnip sized. You can mow it down or even pull it out. It has to be dug out.

“It’s almost impossible to get rid of,” Conroy said. “But it’s on sale because it’s pretty. People like the look of it. It’s used in flower arrangements.”

There are 21 plants considered noxious weeds across all regions of the province — designated by the Ministry of Forests, Lands and Natural Resource Operations (FLNRO). There are others considered noxious on a region by region basis. The East Kootenay has an additional four species listed as noxious.

Knapweed, for example, is Eurasian in origin, and probably came over to these parts with contaminated feed in the 19th century. It has since spread over North America, choking out native plant species.

“There are as many as 100 other species not on the (noxious plant) list,” Conroy said. “But it’s only a matter of time for many of them.

“There is a watch list,” she added. Some weeds aren’t even in B.C. yet, but they’re headed our way.”


Pictured: Tamarisk has been an “environmental disaster” along the Colorado River riparian. Given climate change, in 20 years it could be an environmental disaster for the East Kootenay (

Knotweed is an example of a plant that can be found for sale in horticulture shops in our region. The bamboo-like plant produces beautiful foliage, and can grow up to 10 metres high, given the right conditions. And it is immensely destructive. It’s roots grow 15 feet deep and 30 feet wide. No other plants can survive in the vicinity.

“It will exploit any crack in cement or asphalt, and will cause damage to sidewalks, house foundations, pipes — any infrastructure,” Conroy said.

Conroy sited the example of a Kimberley resident, who had knotweed spread to his property from a neighbour’s. “He sprayed it, he’s taken a blowtorch to it, he’s tried to dig it out — he just can’t get rid of it,” she said.

Knotweed has become an immense problem in the United Kingdom — like a science fiction horror out of “The Day of the Triffids.” See more at

“Knotweed is a big problem in the UK, it’s a big problem in the Lower Mainland, and it’s just arriving here,” Conroy said. “And it is for sale locally.”

A part of the issue is that the horticulture industry is unregulated, Conroy said. “So whatever the distributors are pushing — something that’s beautiful, that’s trendy, that’s vigorous, that grows easily — the stores are pressured into taking their product.”

Conroy added that many retailers are unaware that invasive seeds are unintentionally mixed in with seed mixtures. “For example oxeye daisy, and yellow toadflax are common seeds in almost all ‘wildflower’ mixes.

“These seed mixes typically list less than half of the ingredients, and up to 40 per cent of the seeds that germinate in the mixes have been found to be invasive and on prohibited or noxious weed lists of many states and provinces, and these plants are not included on the packaging.”

There are many other examples of invasives that are for sale in the East Kootenay. Some species of spurges, for example, which can be extremely toxic to humans and animals. It can cause blistering and scarring on skin by removing the skin’s ability to filter sunlight.

Mountain Bluet (for sale) is spreading through the alleys and roads of Kimberley. If it, or oxeye daisies, were to get into the alpine or subalpine areas, it could be disastrous, Conroy said. Oxeye daisy has already taken over Manning Provincial Park.

Conroy knows that purple loosestrife has been purchased in the region. The EKIPC spent several days this summer pulling the weed out of Bummer’s Flats, home of the endangered leopard frog. “Purple loosestrife will create a monoculture in wetlands,” Conroy said. “It can choke out wetlands, changing the water quality, dropping the water table, harming wildlife.”

Tamarisk, on sale in the East Kootenay, is the most invasive plant in riparian areas It has wiped out natural vegetation along the Colorado River. “Bird populations have crashed,” Conroy said. “It’s been an environmental disaster. And as climate changes, 20 years from now it could be disastrous for the East Kootenay.”

Conroy said this situation “is just something that’s opening up to our understanding. We’re asking for awareness on the part of the consumer and retailer, and a willingness for retailers to operate under best management practices and understanding the larger implications.”

To this end, the EKIPC is offering a complete information package for home gardeners and retailers to research and educate themselves on the possible effects of plants they’re planting or carrying on their shelves. This includes the EKIPC’s “Plantwise” certification program, whereby retailers in the horticulture industry take steps to reduce the sale of invasives. Winderberry Nurseries is Windemere is one such local business getting its Plantwise certification.

“They’re working with the Invasive Species Council of BC to eliminate invasive species from their stock,” Conroy said.

“But even if the horticulture industry was required to inform customers about possible invasive or animal/human health issues, that would be an improvement over the present unregulated free-for-all that the industry currently appears to be,” Conroy said.

The EKPIC will be holding a series of workshops on invasive species this fall. For more information, contact the East Kootenay Invasive Plant Council at, or call Cathy Conroy at 1-888-55EKIPC.