It’s a terrible irony that the gardens we plant to make our environments more beautiful can damage the natural world outside our fences. By now, we understand the harm caused by the improper use of pesticides and the over-use of chemical fertilizers. But are you aware that many of our garden plants are from foreign ecosystems, wreaking havoc on our local environments?
An invasive species is one that, when introduced into a new environment, spreads so aggressively that it harms the function of the ecosystem into which it has been introduced. For instance, invasive species displace native plants that wildlife depend on, alter hydrology or soil chemistry so that native plant communities can no longer thrive, and create vast monocultures that eliminate habitats and reduce biodiversity. Unsurprisingly, invasive species can also have an immense economic impact and even threaten human health.
One of the ways that invasive plants spread is through the gardening and horticulture trade. Accordingly, gardeners have a responsibility to help prevent the spread of invasive plants. To become a wiser gardener and consumer, look out for these red flags the next time you’re plant shopping:
· Exotic: Invasive plants, by definition, are non-native species that were introduced to our ecosystem. They might be labelled as “exotic” or contain a reference to a faraway land in their name, like Himalayan Blackberry. However, not all exotic plants are invasive (tulips are a good example)!
· Hardy, resistant, easy to grow, tough to kill: Invasive plants often require minimal care, making them both a blessing and a curse. If a plant is being advertised as easy to grow or resistant, do a bit more research to ascertain its invasiveness or email us with any questions.
· Showy flowers, prolific seeder, self-seeding: More flowers mean more seed production, and self-seeding means a plant doesn’t need a companion to reproduce. Both can be hints that a plant might behave invasively.
· Disease and pest resistant: Areas of invasive species introductions typically lack their natural control measures. Without predation, pests and diseases, invasives can run amuck.
· Fast-spreading: Plants that reproduce by suckers (vegetative shoots arise from shoots) or are said to create a dense mat are often invasive; Common Periwinkle and Yellow Lamium are good examples.
· Widely adapted to a variety of cultural conditions: This may seem counter-intuitive, as highly-adaptable plants are also a gardener’s dream, but they might become your worst nightmare! Plants that can thrive in varied light, soil and moisture conditions could be a red flag, especially if combined with the other characteristics above.
· Known to be invasive in other regions: If a plant is considered invasive, ‘weedy’ or undesirable in other regions, chances are it’s the case here too! If you are a beginner gardener, pay attention to what your gardening friends, locally or afar, say about particular plants. You may learn more than you expected!
While this all may seem overwhelming, fear not! The Grow Me Instead guide provides a variety of native and exotic plant alternatives found to be non-invasive across the province, which you can download for your next visit to the nursery.
In the meantime, put your invasive plant ID skills to the test by participating in our weekly I Spy in the Sea to Sky. Whether you guess right or wrong, you’ll be entered to WIN a packet of native seed mix! Follow SSISC on Facebookor Instagram to learn more about the contest (every Monday)!
Looking to take it one step further? SSISC’s online Invasive-Free Certification program integrates targeted invasive species management into the practices of horticulture, landscaping and earth-moving to help with habitat conservation. The Invasive-Free Certification has gone virtual and is launching soon!