Weed Control
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Diffuse Knapweed
Information | Images
Centaurea diffusa
Biennial or short lived perennial
Identification and management tips
- Flowers are predominantly white, occasionally pink-purple.
- Bracts end in sharp, rigid spines with the terminal spine being distinctly longer. Sometimes can have black spots, but will always have a terminal spine.
- Diffuse knapweed can be readily controlled with herbicides. However, the weeds will reinvade unless cultural techniques are used!
- For small sites with limited distribution, pull or dig up plants and remove as much root as possible so the plant will not re-sprout. Roots tend to break off four to six inches beneath the ground.
Most effective control methods and timing
| March | April | May | June | July | Aug | Sept | Oct |
|---|---|---|---|---|---|---|---|
|
Mech Chem |
Mech Chem |
Mech Chem |
Mech Chem Cult |
Mech Chem Cult |
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.
