Knapweeds (Diffuse & Spotted & Russian)

Centaurea diffusa & Centaurea stoebe & Rhaponticum repens

  1. Biennial (diffuse) or perennial (spotted & Russian) with long tap root; deeply lobed leaves; contain allelopathic chemicals that supress growth of other plants; spotted knapweed has pink to purple-coloured flowers while diffuse has white flowers; Russian knapweed has white to pink flowers with membranous bracts.
  2. Hand pulling; herbicide control early in the growing season while still green; biological control agents; trained livestock grazing.
  3. Saskatchewan Invasive Plant Species Guide
    Identification Guide for Alberta Invasive Plants
    Weeds of the Prairies
    WeedsBMP App BC – iOS | Android