Latin Name: Knautia arvensis

Origin:  Europe

Physical Description: A perennial herb from a taproot. The stems are erect, hairy, sparsely branched, and can grow up to 1.5 m tall. There can be one or several stems per plant, with little or no branching on the upper stem. The basal leaves tend to be lance-shaped, have pointed

tips, and the margins can be entire or coarsely toothed. Stem leaves are opposite, deeply lobed and are attached directly to the stem. The flowers consist of clusters of violet-blue to purple florets arranged into flower head that resembles a single flower. The flower head has a ring of narrow green bracts immediately below it.

Habitat: It prefers loose, loam soils that are nutrient rich and moderately moist to dry and are often found along roadsides, in pastures, meadows and idle areas.

Impacts:  This rapidly spreading weed is very competitive with forage stands and native pastures. Infestations result in significant declines in hay production and pasture carrying capacity

Reproduction:  Reproduces by seed. A single plant can produce up to 2000 seeds that remain viable for many years.

Mechanical: Cutting or mowing before seed set can reduce seed production. Grazing pastures early can also be effective as cattle will eat young plants but ignore the unpalatable flowering stalks later in the season. Pulling small infestations of immature plants is feasible however pulling more mature infestations is seldom effective due to the difficulty in removing the long, branched roots. Field scabious can be controlled by cultivation. Heavily infested pastures/hayfields can be cultivated and rotated to an annual crop.

Chemical: Several herbicides with the following active ingredients can control Field scabious: picloram, 2, 4-D, glyphosate and metsulfuron-methyl. For available products, contact your local agri-supply store. Prior to any herbicide application, read and follow the label instructions

Biological: None available

Additional Resources:

Alberta Invasive Species Council- Field Scabious Factsheet