⚠️
No photo available yet
Submit a photoDiffuse Knapweed
Centaurea diffusa
⚠️ NOXIOUS — a bushy annual or biennial knapweed from Eurasia with many branched stems and small white or pale-pink flower heads bearing spiny bracts. When mature, plants detach at the base and roll as tumbleweeds, scattering seeds across huge distances. Like Spotted Knapweed, allelopathic and a serious rangeland threat.
Quick Facts
Distribution
Southern Alberta rangeland
Light
Full sun
Bloom Time
July–Sept
Soil
Dry well-drained rangeland
Water
Low
Use Caution— Sharp bracts can injure paws and eyes
Growing & Cultivation
Propagation
DO NOT PROPAGATE. Control: herbicide in rosette stage; hand-pull before seed set for small patches. Biological control insects as for Spotted Knapweed.
