More detailed information on coastal invasive plants:
Information for gardeners on what plants to choose instead:
The following plants are potential invaders or recent invaders. Their spread can be curtailed through vigilance. Please watch for, and report the location of these species.
To report a sighting on Salt Spring Island Click HERE
Or to report to the Invasive Plant Council of BC Click HERE or phone 1-250-392-1400.
Giant hogweed (Heracleum mantegazzianum)
This tall plant shows spotted leaf stalks and purple/red colour on the stems. It shades and kills native vegetation, increasing risk of erosion. CAUTION: Touching the plant can result in a painful skin inflammation. Classified as a noxious weed under the BC Weed Control Act. Giant hogweed look-a-likes
This aggressive grass has flattened drooping flowers on very short stalks, and hairs on the leaf edges and stem.
This plant crowds out native vegetation, especially around wetlands.
The purple flowers are set close along the stem (a "spike" arrangement)
and usually each have six petals. The stem is square in cross-section. Classified as a noxious weed under the BC Weed Control Act.
This hairy-stemmed low-growing (up to several centimeters) feathery plant with divided
leaves carpets the ground and produces seeds with hazardous spines. On Salt Spring the
infestation appears confined to Ruckle Park, but has spread to many locations on the BC coast.
These large-leafed plants with tall bamboo-like stems and small white/green flowers can shade out native plants, especially near wetland areas. Classified as a noxious weed under the BC Weed Control Act.
This attractive plant with three upward-pointing petals forms thickets in wetlands and severely reduces water flow, displacing native plants and damaging wildlife habitat.. Plant fragments may be spread and develop into new infestations. Any yellow iris growing in a wet area is yellow flag iris. Classified as a noxious weed under the BC Weed Control Act.
A number of Euphorbia species are highly invasive, can chemically inhibit other vegetation, and can induce blisters in humans and animals. Leafy spurge, a designated Noxious Weed, has tiny yellow/green flowers on heart-shaped yellowish bracts. Cypress spurge, which has been reported on Salt Spring, is toxic to people and livestock.
Classified as a noxious weed under the B. C. Weed Control Act, this snapdragon-like plant can form thickets that crowd out native species. Classified as a noxious weed under the BC Weed Control Act.
Blueweed invades meadows, pastures and rangelands, therefore infestations are associated with some economic losses.
Also known as Old Man’s Beard, this fast-growing vine clambers up trees and forms a dense canopy, depriving other plants of sunlight. It grows in a wide variety of habitats, and is spreading quickly on Salt Spring.
Also known as Policeman’s Helmet, this plant is extremely invasive in moist, natural areas. It displaces native plants, but dies back in winter, leaving soils exposed and subject to erosion.
Marsh Plume Thistle
Typically a tall, single, slender, unbranched stem covered in spiny wings with a cluster of purple flowers at the top. It can invade moist fields and meadows, replacing native vegetation and reducing forage for wildlife and livestock or form dense stands that compete with tree seedlings.
Wild Chervil and Bur Chervil (Anthriscus spp)
Wild chervil invades pastures and hayfields, reducing forage available for grazing animals and causes molding in hay crops. It can also be a host for a virus that attacks carrot, celery and parsnip crops. Both species can form dense stands that compete with native vegetation in moist meadows and riparian areas. Classified as a noxious weed under the BC Weed Control Act.
At least 175 species of exotic plants have escaped into the forests of Salt Spring Island.
Shown below are some examples of particularly aggressive plants that should be removed when encountered.
This evergreen shrub with yellow pea-like flowers may cover sunny meadows choking out native vegetation and creating a fire hazard.
Gorse is a spiny shrub with yellow pea-like flowers. It can displace native plants and is a fire hazard due to its oil content. Classified as a noxious weed under the BC Weed Control Act.
This plant with daisy-like flowers may exceed one meter in height. It can cause liver damage to animals that feed upon it. Classified as a noxious weed under the BC Weed Control Act.
Canada Thistle (Cirsium arvense)
Credit: Richard Bartz
Canada thistle grows in sunny areas and can crowd out native grasses. Classified as a noxious weed under the BC Weed Control Act.
The prickly canes of this plant may exceed 10 meters in length, creating dense thickets that shade out native plants.
Spurge laurel is a very hardy shade-tolerant plant that grows well in the wild and can compete with native vegetation. Removal requires caution as touching the plant can result in skin irritation.
English Holly (Ilex aquifolium)
Holly is spread widely by birds, and adapts to a variety of habitats. It grows quickly and casts deep shade, depriving native plants of light, nutrients and water.
Butterfly Bush (Buddleja davidii)
Previously recommended for attracting butterflies, this bush is common on Salt Spring and is now considered invasive in southern BC. It spreads rapidly and displaces native vegetation in disturbed areas, forest edges and sunny stream-sides.
Periwinkle (Vinca minor and Vinca major)
Both species of periwinkle grow rapidly and adapt to a variety of conditions, forming dense mats that suppress and out-compete other plants.
Yellow Archangel or Lamium (Lamium galeobdolon or Lamiastrum galeobdolon)
This plant is often sold in hanging baskets or as a groundcover. It spreads aggressively in woodlands and riparian areas, climbing over and killing native plants and forming dense mats of roots which deplete the soil.