EMERGENCY: There is currently 1 INCIDENT.

Meadow Knapweed - Centaurea pratensis

Description: Meadow knapweed belongs to the Sunflower family. This plant is native to Europe and was thought to be introduced to North America as a contaminant in alfalfa seed (Ball et al 2006). Meadow knapweed can grow up to 1m tall. It has lance-shaped basal leaves. Several large purple-pink flower heads form at the top of its branched, hairy, erect stems. This species of knapweed is considered to be a hybrid between brown and black knapweed and is often confused with those knapweed species as well as Spotted knapweed. Meadow knapweed reproduces solely by seed (Ball et al 2006).

Type: Perennial Forb

Habitat and Impacts: Meadow knapweed has been known to invade rangelands and pastures, reducing carrying capacities and yields (Ministry of Agriculture, Lands, and Fisheries, 2002).

Method of Spread: Meadow knapweed reproduces primarily through seed however it can re-grow from root and crown fragments. Seeds germinate throughout the growing season and plants typically flower from May to July. The seed is spread via humans, wind, and animals and can remain viable in the soil for several years.

Location: occurs in the Bella Coola Valley along the Tote road (currently unmapped), and outside the CCCIPC area along HWY 97 approx 0.5km north of Loch Lomond in the TNRD and possibly north of Lac Des Roches (not confirmed).

Management Options:

Mechanical: seed production can be reduced by mowing and hand pulling plants prior to flowering and seed production.

Chemical: Picloram, dicamba, or a combination of clopyralid and 2,4-D are a few of the herbicides that effectively control Meadow knapweed. (Ministry of Agriculture, Lands, and Fisheries, 2002).

Biological: several biological control agents are used to control Meadow knapweed. These include Larinus obtusus (seed feeding weevil), Metzneria paucipunctella (seed feeding moth) and Urophora quadrifasciata (seed feeding fly) (Ministry of Forests and Range, 2007).

CCCIPC Priority and Treatment Strategy: Priority 1 (new invader)

Treatment Options:

Local Level – Frequently mowing and hand pulling small infestations.
Landscape Level - Chemical control and possible biological control for larger infestations.

Meadow Knapweed flowers

Meadow Knapweed plant


Invasive species profile taken from the Cariboo Chilcotin Coast Invasive Plant Committee Invasive Plant Regional Strategic Plan

Page last modified: October 30, 2018 09:44:02 PDT