Weed Control
Home ⟩ Noxious Weeds ⟩ Pink and Purple Flower Plants ⟩ Russian Knapweed
Russian Knapweed
Information | Images
Centaurea repens
Creeping perennial
Identification and management tips
- Russian knapweed flowers are pink or purple colored with papery tip bracts.
- Russian knapweed is toxic to horses at all life stages of the plant.
- It can form dense stands because of its’ allelophathic properties, meaning it releases a biochemical into the soil that inhibits the growth of other plants.
- The keys to controlling Russian knapweed are to 1) stress the weed and cause it to expend nutrient reserves in its root system, 2) eliminate new seed production, and 3) control its vegetative spread.
- The best management plan includes cultural methods combined with mechanical and/ or chemical control techniques.
- In most circumstances, chemical treatments alone will not provide effective control.
Most effective control methods and timing
| March | April | May | June | July | Aug | Sept | Oct |
|---|---|---|---|---|---|---|---|
|
Prev Mech Chem |
Prev Mech Chem |
Prev Chem |
Prev |
Prev Mech Cult |
Prev Mech Cult Chem |
Prev Mech Cult Chem |
Prevention (Prev) Monitor and destroy new plants before seed production.
Mechanical (Mech) Hand pulling, digging, cutting, mowing and tilling.
Cultural (Cult) Biological control agents, livestock grazing, and revegetation practices.
Chemical (Chem) Selective herbicides based on the plant and the specific location. Check our weed fact sheets for specific control information.
Links
Photo credits
Left to right:
- Steve Dewey, USU