Invasive Plants & Alternatives
BC is a large and diverse province with a variety of growing conditions. There are currently two systems used for classifying hardiness, the Canadian Hardiness Zone and The United States Department of Agriculture (USDA) Hardiness Zone System. The information provided here is based on the USDA system due to its current extensive use by gardening enthusiasts, commercial horticulture, and industry professionals.
Zones are based on the annual minimum temperature; zone 1 is coldest, zone 9 is warmest. Select your region and/or specific zone to:
- INVASIVE PLANTS: learn about horticulturally invasive plants that thrive in certain zones to avoid/replace; and
- ALTERNATIVES: find expert-recommended alternative, exotic and native plants to choose instead
INVASIVE PLANTS
Yellow Toadflax
Yellow Toadflax (Linaria vulgaris), also known as common toadflax, is an herbaceous perennial known for its colony forming properties. This invasive species uses creeping roots to rapidly take...learn more
Yellow Archangel
Yellow Archangel (Lamiastrum galeobdolon) is considered a shade tolerant species which is commonly found in hanging baskets and as ground cover. With many methods of reproduction, yellow rchangel...learn more
Tamarisk
Tamarisk (Tamarix chinensis), also known as salt cedar, is a shrub-like tree which has become invasive to riparian areas. This is aggressive woody shrub is known to produce...learn more
Russian Olive
Russian olive (Elaeagnus angustifolia) is a relatively small ornamental tree which has recently impacted several regions in BC. First introduced for its silver leaves and ability to withstand...learn more
Mountain Bluet
Mountain bluet (Centaurea montana) is a popular ornamental plant; its ability to self-seed and large blue flowers make it the top choice among many gardeners. Unfortunately, once planted,...learn more
Flowering Rush
Flowering rush (Butomus umbellatus) is a beautiful aquatic perennial resembling a large sedge. This delicate-almond scented plant can be found along shore lines of lakes or rivers. As...learn more
Daphne
Although it has a poisonous sap, Daphne or Spurge-Laurel (Daphne laureola), is a top ornamental pick for gardens. This species can be purchased at a number of garden...learn more
Common Periwinkle
Common periwinkle (Vinca minor) is a small evergreen plant with showy white or purple flowers. This invasive plant is capable of forming dense mats which supress native plant...learn more
Bachelor’s Button
Known as “cornflower” in southern Europe where this annual species is native and a common weed in grain (“corn”) fields. Bachelor’s button has striking...learn more
English Holly
English holly (Ilex aquifolium) is grown for its bright red berries and spiny, dark green evergreen foliage. A large shrub or small tree, English holly has...learn more
English Ivy
English ivy (Hedera helix) is an evergreen vine that is recognized as a serious, smothering invasive in much of southwestern BC. It is commonly planted to...learn more
Himalayan Balsam
Himalayan balsam (Impatiens glandulifera) is an exotic-looking annual that has pink, helmet-shaped flowers (also known as "policeman’s helmet”), rapid growth, and an entertaining mode of...learn more
Field Scabious
Field scabious (Knautia arvensis) is a perennial plant that competes with forage and pasture land, and is also found along roadsides at mid-elevations of the province. Once...learn more
Baby’s Breath
Baby’s breath (Gypsophila paniculata) is a herbaceous perennial plant that invades grazing land and out-competes native and introduced perennial grasses. Plants flourish in the well-drained sandy...learn more
Butterfly Bush
Butterfly bush (Buddleja davidii) is a deciduous to semi evergreen shrub that grows up to 5 m tall. Until only recently, this species was celebrated for its robust...learn more
Yellow Flag Iris
Yellow flag-iris (Iris pseudacorus) is an eye-catching perennial that creates dense stands in wet areas, excluding native wetland species and threatening plant and animal diversity. Yellow...learn more
Scotch Broom
Scotch broom (Cytisus scoparius) is an escaped garden ornamental, common west of the Coast-Cascade Mountains in southwest BC, and is concentrated at the southern end of...learn more
Purple Loosestrife
Purple loosestrife (Lythrum salicaria) is a woody half-shrub, wetland perennial that has the ability to out-compete most native species in BC’s wetland ecosystems....learn more
Oxeye Daisy
Oxeye daisy (Leucanthemum vulgare) is a short-lived perennial that decreases forage for wildlife, decreases local plant biodiversity, and may compromise vegetative ground cover due to...learn more
Spurges (Leafy, Myrtle, Cypress)
Leafy spurge (Euphorbia esula) is a perennial, considered noxious under the BC Weed Control Act, and commonly found at low- to mid-elevations on...learn more
Himalayan Blackberry
Himalayan blackberry (Rubus armeniacus) is mostly a biennial plant, growing on disturbed sites, along roadsides and rights-of-ways, in pastures, along river and stream banks, fresh-water wetlands,...learn more
Orange Hawkweed
Hawkweeds (Hieracium spp.) are perennial plants with 14 non-native species recorded in BC, and are difficult to identify among the 8 native hawkweed species. One of the 14 non-native...learn more
Giant hogweed
Giant hogweed (Heracleum mantegazzianum) is a perennial and currently distributed in the Lower Mainland, Fraser Valley, Gulf Islands, and central to southern Vancouver Island. Giant hogweed has...learn more
Common Tansy
Common tansy (Tanacetum vulgare) is a perennial and considered regionally noxious under the BC Weed Control Act. Common tansy is currently distributed in...learn more
Blueweed
Blueweed (Echium vulgare) is a biennial to short-lived perennial, and considered regionally noxious under the BC Weed Control Act. Blueweed is commonly found on...learn more
Knotweeds
Knotweeds (Polygonum spp.) are invasive perennials, with four species found in British Columbia: Japanese knotweed (Fallopia japonica); Bohemian knotweed (Fallopia x bohemica);...learn more
