Blue Mountains National Resources Institute

Wanted: DEAD!

Musk Thistle

• Leaves: Up to 10 inches long, dark green with a light green midrib, and spiny.
• Flowers: Large, solitary, purple or deep rose, occasionally white, and nodding. Outer bracts are flat and spreading, ending in spines; inner bracts are narrow and softer. Flowering period starts in June.
• Seeds: 3/16-inch long shiny yellowish-brown and with a hair-like plume.

Musk thistle is a biennial plant that infests pastures, rangeland, and timberlands, and also roadsides, waste areas, ditch banks, and stream courses. It aggressively forms dense stands, crowding out native species. It spreads by seed.

Control:

• Chemical: Herbicides are effective. Call your local weed control office for the latest methods of eradicating this noxious pest.
• Biological: An introduced seedhead weevil feeds on the seeds and limits spread.
• Mechanical: Maintenance of fields and range through fertilization and irrigation helps prevent infestation. Cutting off the rosette below the crown kills the plant, and mowing in bud season can reduce seed production. Burning is *not* advised as it kills the weevils.

Report all sightings to your local Weed Board.