It’s a common sight as summer wanes into fall: hopeful foragers take to their neighbourhood streets, basket in hand, for an afternoon of berry picking.

Chances are, if you’ve walked anywhere in southwest BC, you’ve plucked a ripe blackberry or two. They’re not exactly hard to find.

Have you ever wondered why?

Those blackberry bushes in the park, along the roadside, creeping over your garden fence—they’re doing what any invasive species does: they’re taking over.

And although they might give us tasty fruit, these pushy plants are not good news.

Himalayan blackberry is just one of many invasive plant species to be found on Vancouver Island. Invasive species are most often introduced by humans, and these blackberries are no exception. 

Marketed as a robust, easy-to-grow food crop by horticulturist Luther Burbank in the late 19th century, these plants quickly established themselves in an ecosystem unprepared to deal with them. Today, they extend their thorny tendrils all over the Pacific Northwest, and they’re the bane of gardeners everywhere.

It’s the same story with dozens of other plants. With no natural predators to keep them in check, invasive plants spread fast, get aggressive, and choke out the competition.

What was once a diverse meadow or thriving wetland could become a uniform thicket of blackberry brambles in only a few short years.

Some of them are familiar. Blackberry bushes, for example, are easy to recognize once you spot those telltale thorns and berries. 

And those yellow flowers you see stretching for hundreds of metres along the side of the highway? That’s Scotch broom, another invasive. It might look pretty, but it’s one of the most aggressive growers around, and they greatly increase the risk of wildfire.

Then there’s English ivy—you might not know its name, but you’ve certainly seen it climbing buildings and trees alike. In fact, English ivy can grow so vigorously that, if left unchecked, it will weaken whole trees and leave them susceptible to toppling.

Invasive plants have far-reaching impacts across environmental and societal areas of life. Their growth can cause everything from soil erosion to declines in essential pollinators—and their sheer size and abundance can render recreational areas like parks and trails physically inaccessible.

Luckily, there are people striving to fight back.

The Nanaimo & Area Land Trust (NALT) is a nonprofit organization dedicated to restoring and preserving Nanaimo’s land and water systems. Founded in 1995, NALT promotes biodiversity, protects important ecosystems from urban development, and engages the community in conservation efforts.

Although managing invasive plants is just one small piece of their broader work, they have a lot to say on the subject.

Linda Brooymans, stewardship manager for NALT, shares why invasive plants are such a serious issue.

“It leads to biodiversity loss in that specific habitat, and that has cascading effects for everything that lives in that habitat,” Brooymans explains.

“So, you see population declines of other organisms, whether they’re plants or animals.”

And if you’re wondering why they seem to be everywhere—like those blackberries in the parking lot—the answer is elegantly simple.

“They are really well adapted to taking advantage of disturbance,” Brooymans says.

“Sadly, basically any human activity counts as disturbance. Whether it’s a hiking trail, or development, or any kind of impact on an ecosystem.”

When humans alter the land, we inadvertently open the door to some unwelcome guests. By definition, invasive species are opportunistic lifeforms.

Once they’re in, they can be extraordinarily hard to get out. With a huge supply of seeds that can sometimes stay dormant in the ground for decades, invasives put up a doozy of a fight.

“It’s often a question of managing them as best as we can rather than eradicating them,” Brooymans says. “And it’s never a one-and-done kind of situation when you’re tackling invasive species in a habitat. You have to often come back year after year, and you have to really play the long game in terms of recognizing that you’re gonna have to keep coming back and pulling seedlings.”

The job doesn’t stop there. She warns that pulling out the plants is only half the battle.

“You have to plant native plants because removing the invasives is its own type of disturbance,” she says. “And so, sometimes, if you just remove and don’t replant anything, you’ll see a whole new crop of invasive species.”

The strategy is often containment-focused. Focusing on areas with high biodiversity, NALT works to limit the spread of invasive plants into those areas. It’s the most feasible way of protecting as much land as possible.

If the whole thing seems overwhelming, remember: everyone has the power to help.

For those at home, Brooymans suggests starting with curiosity. Observing your own garden can make a big difference.

“If you see a new plant growing in your garden, try and figure out what it is, and then see if it’s invasive, because if it is, you should remove it. That’s how the spread happens.”

Apps like Seek by iNaturalist allow you to identify a species with your camera, and the iNaturalist site is a great resource that connects you with scientists, researchers, and fellow community members around the world.

When in doubt, you can always check the Invasive Species page on the City of Nanaimo website, as well as the sites for organizations such as the Invasive Species Council of British Columbia and the Coastal Invasive Species Committee.

Identifying your plants is important when shopping, too. Currently, there is no provincial regulation on the sale of invasive plants. That means the responsibility falls to the consumer to make wise choices.

Just because it’s in a garden centre doesn’t mean it’s safe.

“There’s one plant called Himalayan balsam which is spreading all through Departure Creek Watershed,” Brooymans says. 

“One person bought it at a garden centre because it looks really pretty. And bees love it. But as a result, it produced thousands and thousands of seeds, which then flowed downstream and established all throughout the stream banks.”

The Himalayan balsam crowds out native plant species in local stream banks, only to die in the fall, leaving soil bare for the winter. Brooymans explains that the soil will then wash into the stream, causing a buildup of sediment in fish habitat. One invasive plant could lead to a whole ecosystem collapse.

For those who want to contribute to NALT’s efforts—including various stewardship projects and a native plant nursery—Brooymans encourages visiting their website. “We’re always looking for volunteers,” she says.

As for other things you can do, local conservationist Hunter Jarratt (also known as the “Invasive Species Guy”) stresses the importance of avoiding cross-contamination when you’re out and about.

“Making sure you’re cleaning your gear, washing your boots, or, if you notice there’s a bunch of seeds on your jacket or stuck to your dog, checking that those aren’t being spread to a new area is huge,” Jarratt says.

He goes on to add: “When people go off-trail, they can spread these seeds to areas where they’ve never been before. A lot of them have little burrs and hairs that make it really easy to connect to things, and then they can persist in the soil for a long time.”

Jarratt has worked in invasive species management for over five years. A graduate of Vancouver Island University’s (VIU) natural resource protection program, he has experience working with both the Invasive Species Council of British Columbia and the Coastal Invasive Species Committee.

Even before that, he worked with BroomBusters, a nonprofit grassroots organization dedicated to cutting and removing Scotch broom.

These days, Jarratt is pursuing a Restoration of Natural Systems certificate at the University of Victoria. He also does advocacy work and offers consulting services for people looking to manage the invasive species on their properties.

One of the biggest challenges in Jarratt’s experience, it turns out, is disposal.

Many invasive plants like English ivy and periwinkle can revegetate from pieces of plant matter—so by throwing them in the compost, you risk encouraging more growth. General disposal recommendations encourage isolating the material in a bag and throwing it away in the trash, but Jarratt raises the limitations of such methods.

“In many cases there’s so much biomass,” he shares. “It’s just not feasible.”

For example, he points out that Scotch broom can fill a garbage bag with just one or two bushes—and in many places, there are enough bushes to form a forest. That adds up to a lot of bags and a lot of extra labour.

“It’s just this big mess—they poke through and there’s not enough volunteers. It’s kind of soul-crushing, and a lot of volunteers with different groups just decided to be done because it’s a big barrier.”

That being said, management isn’t a lost cause. Jarratt shares several disposal methods that work.

“Certain invasives are way easier to bag,” he reassures. These include English ivy, common and greater periwinkle, and yellow archangel. Even blackberry roots can be bagged without too much trouble.

In other cases, disposal facilities might not require bagging because they treat invasive plant material like hazardous waste—it goes into deep burial so it cannot spread. 

There are even rare times when burning is appropriate; it all depends on the context.

He emphasizes: “You really just have to know the organization that you’re going to be bringing your materials to.”

With all the challenges associated with tackling invasive plants, it can be easy to feel powerless.

But change can start one little garden at a time.

Dr. Caroline Josefsson, a biology professor here at VIU, is taking an active role in restoration. In 2021, Josefsson and the VIU Ecology Club began a collaboration that has since involved over 100 volunteers and more than 1,000 hours of work: the B470 plot.

Situated near the top of campus, the B470 plot is a fenced plot of land home to roughly 90 locally adapted plants. Volunteers removed all non-native plants from the site and continue to care for the restored land.

It even has a younger sibling; last year, the B473 plot was created just a short walk away.

“The species composition in our two sites reflects the ‘Garry oak ecosystem,’” Josefsson says. “[It’s] the Western Scientific term for an extremely biodiverse ecocultural landscape, adapted to the distinct climate of southeastern Vancouver Island, and managed by Coast Salish people for millennia before colonization.”

Josefsson shares that “while the ecosystem hosts a multitude of insects, birds, and other animal species, it also contains many important traditional foods and medicines.”

She says the project’s main goal is to raise awareness of native plants and their positive effects on the environment. The project also offers seeds to those who want to start their own native gardens.

“Our two restoration sites serve as an example of what native plant restoration can look like in practice,” Josefsson explains.

She encourages interested folks to get involved.

“Anyone can join our project; we have volunteers from all faculties on campus, and there is no previous knowledge needed. We have tools and gloves available, so you don’t need any special equipment to join.”

And if you’re still not sure, consider that when you take care of nature, you are also taking care of yourself.

“Doing something hands-on that directly improves our local environment is a constructive way of coping with climate anxiety,” she says.

So, the next time you’re up by the Environmental Sciences building, why not swing by the plot to see some current restoration in action?

And the next time you encounter a plant you don’t know—whether that’s at the store, on a trail, or in your own yard—remember these cautionary tales, and choose your next move carefully. You just might be up against a pretty formidable foe.