Escaped garden plants choking London’s Environmentally Significant Areas, should invasive species require warning labels?

With non-native invasive species creeping into environmentally significant areas, why are nurseries allowed to sell them? CTV London’s Daryl Newcombe explains.

Invasive plants are threatening London’s most sensitive ecosystems, and the source of the problem might be your own backyard.

Last week, the Environmental Stewardship and Action Community Advisory Committee (ESACAC) recommended that council amend the municipality’s business licensing by-law to require that retailers of invasive plant and animal species be required to provide point-of-sale education.

The approach would be similar to educational requirements placed on fireworks retailers in London.

“The best way of preventing it is by educating people so that they don’t accidentally plant the wrong [species] in the first place,” explained Dr. Brendon Samuels, a member of ESACAC.

During a walking tour of the Kilally Meadows Environmentally Significant Area (ESA), Dr. Samuels showed where English Ivy has grown under a backyard fence and into the woods, crowding out the native plant species.

“Someone probably planted a small English ivy plant years ago, not realizing that it would spread under the fence and into the ESA behind their back yard,” he said.

“It’s the exact same species that I just picked up around the corner at a store,” Samuels added. “[It] isn’t labeled to warn the consumer this could cause environmental and property damage.”

Further down the pathway, a thick carpet of periwinkle is preventing native species from growing.

Near another entrance to the same ESA, goutweed (ground elder) plants have choked out most of the other plants species on the forest floor.

Gardening in a front lawn less than a block away from The Coves ESA, Londoner Paula Martin believes point-of-sale information would be effective.

“That information would be helpful for people just like me because I don’t know a lot about it,” she told CTV News. “I could be educated at the same time.”

London has 21 ESAs that are home to native, rare, and endangered species.

According to Samuels, they also all contain invasive species that either escaped nearby gardens or were the result of potted plants being discarded in the woods, “They can completely take over an area, changing the composition of the soil, blocking out light for native plants, making it really difficult for other species that belong in this environment to coexist.”

Samuels doesn’t believe banning invasive plants would be effective because determined gardeners could drive to neighbouring municipalities.

“The supply chains for these products are much larger than London,” he told CTV News. “I would rather not restrict people from acquiring these products that they want, but instead, we need to make sure that they’re informed about how those products should be used and how they should be disposed of to minimize the risks to the environment and the cost to taxpayers.”

One of the simplest solutions is to grow invasive species in a flower pot.

The advisory committee consulted with several local independent greenhouses and nurseries.

Its report explains those business owners expressed support but noted, “Without a uniform city-wide approach, businesses that voluntarily restrict such sales could be placed at a competitive disadvantage, while businesses continuing to sell invasive species may continue to profit from them.”

The ESACAC report suggests that prevention through education can be cost effective.

“Management for these invasive species is really expensive and it takes a long time. Depending on how bad an outbreak is, it could take many years,” Samuels recalled.

The advisory committee’s recommendations will be considered by councillors at the next meeting of the Community and Protective Services (CAPS) Committee.

The ESACAC report lists several invasive plant species that can be difficult to eradicate once they become established within an ESA:

• Lily of the Valley (Covallaria majalis)
• Periwinkle (Vinca minor)
• English ivy (Hedera helix)
• Burning bush (Euonymus alatus)
• Common lilac (Syringa vulgaris)
• Carpet bugle (Ajuga reptans)
• White mulberry (Morus rubra)
• Daylilies (Hemerocallis fulva)
• Yellow flag iris (Iris pseudacorus)
• Japanese barberry (Berberis thubergii)