Common Noxious Weeds in Alberta – Field Scabious

Field Scabious (also known as Knautia arvensis) is a perennial weed that can reach up to 1.5 meters in height.

Perennial weeds grow from root stalks year after year.  Perennial weeds spread by seeds and roots, and therefore the entire plant must be destroyed.

Classification: Noxious Weed

Recognizable features:

Key Traits:

  • Pink-blue flowers growing in a cluster that look like a single flower
  • Stiff hairs cover the entire plant

Stem: Erect, hairy and sparsely branched. One or several stems per plant.

Leaves: Hairy and variable degree of lobes. Lower rosette leaves are generally lance-shaped with pointed tips. “Stem leaves are opposite, deeply lobed, and attached directly to the stem. Lower leaves can grow to 25 cm long but become smaller higher on the plant.” (Source: Government of Alberta)

Flowers:  “Flowers are a composite of small violet-blue to purple florets clustered into a head resembling a single flower up to 4 cm wide, and occur singly at the ends of stems.” (Source: Government of Alberta) A ring of narrow green bracts can be found below the flower head. “Once flowering is complete the seed head is domed and covered with short bristly hairs.” (Source: Government of Alberta)

Green Oasis offers a variety of weed control services to help you get rid of pesky weeds.

Contact your local office to learn more:

Calgary:                                                                Red Deer:

Tel:  403-206-9900                                             Tel:   403-358-3339

Email: CALGARY@GREENOASIS.CA               Email: REDDEER@GREENOASIS.CA

Information compliments of:

Government of Alberta, Field Scabious Information Sheet