Have you ever found yourself wondering, “Wait… is this plant invasive, or just a weed?” you’re not alone.
At CKISS, we get this question all the time, and for good reason. The language used around plants, animals, and invasive species can be confusing. Terms like invasive, noxious, native, naturalized, weed, and pest are often used interchangeably, but they actually mean very different things. And those differences really matter when it comes to how we protect and care for our ecosystems.
So let’s clear it up! Below, we break down some of the most common terms you’ll hear in the invasive species world, using examples from right here in the Central Kootenay region.
Native Species: Born and Raised
Let’s start with the most straightforward one. Native species are plants, animals, or fungi that have evolved in a specific region over thousands of years. They naturally occur in the area without human introduction and are deeply connected to the local ecosystem.
They have evolved to support native wildlife, help maintain biodiversity, and are often well adapted to local conditions.
Examples: Western redcedar, Saskatoon, or the Nootka rose, all iconic BC natives.
Invasive Species: When Things Get Out of Hand
This is the big one. Invasive species are non-native organisms that have harmful impacts, whether that’s ecological, economic, or even health-related (social). They often spread aggressively, outcompete native species, and can seriously disrupt ecosystems.
They may lack natural predators, reproduce rapidly, or simply dominate a landscape where they don’t belong.
Here in the Kootenays, we’re dealing with some tough invaders like:
Japanese knotweed (damages infrastructure and riverbanks)
Scotch broom (increases wildfire risk and chokes out native plants)
Zebra mussels (not established in BC yet, but a huge threat to our lakes)
These species pose major threats to our ecosystems and economies alike. That’s why they’re top priorities for CKISS.
Naturalized Species: Immigrants Who Fit In
Naturalized species are non-native, but they’ve made themselves at home without causing serious problems. They were introduced, often accidentally or through gardening or agriculture, but they DON’T disrupt local ecosystems in a significant way.
A classic example? Dandelions.
They’re originally from Europe but are now found almost everywhere in North America. They aren’t native, and while they’re sometimes annoying to gardeners, they aren’t considered invasive or harmful to ecosystems.
So, while dandelions are weeds in your lawn, they’re not on CKISS’s watchlist.
Noxious Weeds: The Legal Trouble-Makers
Now here’s where things get even more specific. Noxious weeds are invasive plants that are officially listed under BC’s Weed Control Act or Canada’s Wildlife Act. When a species is designated “noxious,” landowners may be legally required to control or remove it.
One of the most serious examples right now? Poison hemlock.
This toxic plant is popping up in places like Creston, and it’s not just invasive, it’s dangerous: it can be lethal if ingested. All parts of the plant are highly poisonous to humans and animals, even with skin contact. Because of this, it’s listed as a noxious weed in BC.
Pests: Not Always What You Think
The word pest gets thrown around a lot, but it’s really just a general term for anything that causes problems for people, agriculture, or homes. It could be a plant, insect, or animal. And pests can be native or non-native.
For example: aphids are tiny insects that damage garden plants by sucking sap. They’re common, annoying, and definitely pests—but they aren’t necessarily invasive. In fact, many aphid species are part of the existing ecological web, even if gardeners don’t love them.
So “pest” isn’t a scientific term, it just depends on the context.
Weeds: It’s All About Location
Lastly, let’s talk about the most misunderstood word: weed.
A weed is simply a plant that’s growing where you don’t want it. That could be a dandelion in your veggie garden, or even a native plant crowding your driveway- we often hear about Horsetail being a major nuisance to local gardeners- this is a weed not invasive!
Not all weeds are invasive. In fact, most aren’t.
A native buttercup in a pasture might be considered a weed, but it’s not invasive or harmful.
On the flip side, an invasive plant like knotweed might look like a lush green bush that landowners like to use as a natural privacy fence, but it’s a serious threat to your property and nearby waterways especially.
Why It All Matters
Understanding these terms helps us figure out where to focus our time, energy, and resources. Not every weed is a threat. Not every introduced species needs to be removed. But invasive and noxious species? Those are the ones we need to act on…fast.
At CKISS, we’re here to help the public:
Learn which species to report
Understand what’s legally required
Make informed decisions in their gardens, farms, and outdoor spaces
Work together to protect the lakes, rivers, forests, and wild places we love
How You Can Help
You can take action right now by:
Reporting Invasives or noxious plants (like poison hemlock)
Choosing native or non-invasive species for your landscaping: learn how here with our EcoGarden program
Sharing this blog to help others understand the difference!