- Knotweed can reproduce through small fragments. Do NOT dig, cut, or mow knotweed as this can stimulate an increased spread!
- Chemical control is the only viable treatment option for large infestations. Click here for a list of Herbicide Contractors in the Kootenays
- Do not grow knotweed in your garden or share cuttings of existing plants. Be PlantWise and use Grow Me Instead to avoid planting knotweeds.
- Native to eastern Asia (Japan, China, Korea).
- There are three varieties of knotweed (Fallopia spp., Polygonum ssp.) present in our region: Japanese, Giant and Bohemian knotweed. All have similar characteristics and concerns.
- Herbaceous perennial.
- Hollow stems, similar in appearance to bamboo.
- Reach 3 – 4 m height
- May have small cream, white, or slightly pink flowers.
- Reproduces vegetatively.
- Adapted to moist conditions, generally shade-tolerant.
- Found throughout the region, mainly along roadsides.
Introduction and spread
- Initially introduced to BC for ornamental use, especially for privacy purposes as it grows rapidly and forms dense patches.
- The plant reproduces through fragmentation, so when small pieces of the plant are moved by mowers, equipment, or other vectors it can allow the plant to spread.
Consequences of invasion
- Invades roadsides, disturbed sites, wetlands, riparian areas, and streambanks.
- Increases erosion and sedimentation of streambanks and riparian areas.
- Decreases fish habitat and has negative impacts on salmonids.
- Negatively impacts infrastructure such as asphalt and house foundations by growing through them.
- May decrease property value.
Status in the CKISS region