What defines an invasive plant?
Invasive Plants
Knotweed
(Chaster Park)
Invasive alien plants are brought to Canada, either accidentally or
intentionally, and include species like purple loosestrife, Japanese
knotweed, and scotch broom, to name just a few. These plants
have the ability to establish quickly and are highly competitive due
to prolific seed production, deep taproots, or early flowering.
Because they arrive in Canada without their natural predators to
keep them in balance, they can spread rapidly, forming dense
patches over large areas and often displacing native plants.
Since animals rarely eat these species, infestations can impact
wildlife habitat and rangeland. Invasive plants can have huge
economic impacts by competing with desirable agricultural crops
and forest plantations. They can also pose significant threats to
human health and safety by causing skin irritation or burns and
reducing visibility along transportation corridors.
English Ivy
(Ocean Beach
Esplanade)
Often mistaken for wildflowers, invasive plants are spreading
through our natural ecosystems, urban landscapes, and agricultural
lands at an alarming rate. Invasive plants are spread through
several key pathways of invasion including increased international,
national, and regional travel and trade; horticulture, gardening and
ornamentals; transportation and utility corridors; seed mixtures
(re-revegetation, birdseed, wildflower); recreation; and wildlife,
livestock, humans, and pets.
For more information, please visit the Coastal Invasive Species
Committee website and their brochure: Invasive Plants on
Vancouver Island, the Gulf Islands and the Sunshine Coast
Second to habitat loss, invasive species have been identified as the most
significant threat to biodiversity. In 2000 (updated in 2004), the World
Conservation Union collaboratively published a booklet identifying 100
of the World's Worst Invasive Alien Species, two of which currently exist
on the Sunshine Coast:
Gorse
(Ulex europaeus)
Butterfly Bush
(Roberts Creek)
Japanese
knotweed
(Fallopia
japonica)
Invasive plants are more than simply "plants out of place"; these
invaders are far-reaching in their impacts, permanently altering
landscapes and ecosystem functions and costing economies millions of
dollars each year.
Disposal of Invasive Plants
Giant
Hogweed
(Maple Park)
Periwinkle
(Ocean Beach Esplanade)
The Invasive Plant Council of BC defines the term "invasive plant" as any
invasive alien plant species that has the potential to pose undesirable or
detrimental impacts on humans, animals or ecosystems. Invasive plants
have the capacity to establish quickly and easily on both disturbed and
un-disturbed sites, and can cause widespread negative economic, social,
and environmental impacts. Many invasive plants have been introduced
to British Columbia without their natural predators and pathogens that
would otherwise keep their populations in check in their countries of
origin. For this reason, invasive plants also commonly referred to as
"alien", "non-native", "exotic" or "introduced" plant species.
The Regional District is in the process of developing
a strategy for the disposal of invasive plants. Until
then, all garden waste (except for Giant Hogweed
which must be bagged and sent to the landfill) is to
be brought to:
Salish Soils, 5800 Black Bear Road (next to Lehigh
Construction Aggregates) 604-885-5383
[email protected]
Monday to Friday 8am-4:30pm
Saturday & Sunday 10am-4pm
Fees may apply for loads heavier than 5 tonnes.
Please note that knotweed MUST be separated.
Examples of Invasive Plants
on the Sunshine Coast!
Knotweed is a tall shrub with bamboo-like stems. It
has been planted throughout South and Central
Vancouver Island and the Gulf Islands as a garden
ornamental but quickly spreads to form dense thickets in
a variety of habitats, including dry roadsides and moist
stream banks. Small patches can quickly spread into large
areas, leaving little room for native species to grow.
Refer to Invasive Knotweed T.I.P.S. recommendations for
information on prevention and control methods.
Scotch broom
is often admired
as a beautiful ornamental species. With
bright yellow flowers and leathery
green stems, it is certainly attractive;
however, it is considered a highly
invasive alien plant. This woody
perennial shrub can be identified by its
yellow pea-like flowers that bloom in
May, and flat brown seed pods
Refer to Scotch Broom T.I.P.S. for
information on prevention and control
methods.
Scotch Broom
(Ocean Beach Esplanade)
Giant hogweed is a perennial member of the Parsley or
Carrot Family native to Asia. It closely resembles our native
plant cow parsnip, except the taller giant hogweed grows up
to 6 metres or more. It was first introduced to North America
as a garden curiosity. Its tenacious and invasive characteristics
have made it a garden pest that can readily escape
cultivation. Giant hogweed sap contains toxic chemicals that
are harmful. Please review recommendations below for
appropriate health and safety measures.
Knotweed
(Chaster Park)
Knotweed
(Chaster Park)
Refer to Giant Hogweed T.I.P.S. for information on
prevention and control methods.
Giant Hogweed
(Maple Park)
Butterfly Bush is an attractive shrub which bees and
butterflies seem to adore. However, it can alter the
proportions of nitrogen and phosphorous in the soil and can
compete with juvenile Douglas-fir in forests.
The plant can be controlled by hand-pulling small plants but
all of the stems and roots must be removed. Larger plants can
be cut to the base or dug up. Stumps can be treated with a
glyphosate or the stump can be covered with a thick plastic
bag or mulch. Remove new sprouts that may appear. If plants
cannot be removed, cut off flower stems before seed set. No
biocontrol is available in Canada.
The seed bearing capabilities of the plant are awesome. A
single flower head can produce 40,000 seeds while
maintaining a better than 80% germination rate. The seeds
remain viable for three to five years; this means great
diligence is required to remove the species completely from
an area.
Interestingly, B. davidii does not compete well in shade. A
garden without direct sun can help keep this pest out. It is
also most competitive in disturbed, compacted and poor soil.
These characteristics make it a prime suspect for stream
banks in areas that have increased runoff from new
development.
Periwinkle
(Ocean Beach Esplanade)
English Holly
And others…
English Ivy
(Ocean Beach Esplanade)
Lamiastrum galeobdolon
(Yellow archangel)
Before you buy… take some time to learn a
bit about the most common invasive plant species in the
region and some healthier alternatives. There are several
brochures that you might find helpful:
Help Stop the Spread of Invasive Plants
Grow Me Instead
Acknowledgments
Butterfly Bush
Most of this information was provided by the Coastal
Invasive SpeciesCommittee.
Reporting Invasive
Plants
Unusual plants that appear to be taking
over or growing out of control should be
reported in one of these ways:
• Toll Free 1-888-WEEDSBC
• Online database, ‘Report-A-Weed,’
Invasive Alien Plant Program (IAPP):
www.for.gov.bc.ca/HRA/Plants/raw.htm
Please report the following information:
1. Species (or plant characteristics and
photos if species is unknown)
2. Size of infestation
3. UTM coordinates or directions to site
4. Your contact information