Himalayan Knotweed
Polygonum polystachum
Physical Description
Himalayan knotweed has several distinct identifying characteristics that help with distinguishing it from other knotweeds. The leaves are much narrower than those of Japanese and giant knotweed and have long pointed tips. The clumping growth habit and comparatively narrow stems cause Himalayan knotweed to form very dense patches that are quite difficult to travel through.
Himalayan knotweed has several distinct identifying characteristics that help with distinguishing it from other knotweeds. The leaves are much narrower than those of Japanese and giant knotweed and have long pointed tips. The clumping growth habit and comparatively narrow stems cause Himalayan knotweed to form very dense patches that are quite difficult to travel through.
- 5-12 inch lanceolate or spear shaped leaf with a pointed tip
- 4-8 feet tall
- Thin, light green, segmented stems
- Green to red colored papery sheaths between stem segments
- High density of stems
- Narrowly hollow stems
- Cream colored, sweet smelling, flower bunches seen mostly at top of stems
Where is it located in Lincoln County?
Himalayan knotweed infestations in Lincoln County are centralized in the urban riparian corridors of Lincoln City and Yachats.
Control Efforts
Himalayan knotweed infestations take several years of treatment to control and the most effective method is repeated herbicide application. Contacting a natural resource professional as early as possible is integral to knotweed control. If you see Himalayan knotweed, contact the Oregon Invasives Hotline as well as Lincoln SWCD by phone at (541-265-2653) or email.
Click the link below for an in-depth summary of current knotweed control practices:
Himalayan knotweed infestations in Lincoln County are centralized in the urban riparian corridors of Lincoln City and Yachats.
Control Efforts
Himalayan knotweed infestations take several years of treatment to control and the most effective method is repeated herbicide application. Contacting a natural resource professional as early as possible is integral to knotweed control. If you see Himalayan knotweed, contact the Oregon Invasives Hotline as well as Lincoln SWCD by phone at (541-265-2653) or email.
Click the link below for an in-depth summary of current knotweed control practices:
