Musk thistle (Carduus nutans)
Quick Facts:
- Biennial plant which reproduces only by seed; to successfully manage musk thistle, prevent seed formation.
- Average plant produces 10-20,000 seeds.
- Seeds may remain dormant in soil for over 10 years.
- Seeds germinate even under relatively dry conditions.

Musk thistle rosette
Musk thistle will not tolerate tillage and can be removed easily by severing its root below ground with a shovel or hoe. Mowing can effectively reduce seed output if plants are cut when the terminal head is in the late-flowering stage. Gather and burn mowed debris to destroy any seed that has developed.
Maintaining pastures and rangeland in good condition is a primary factor for musk thistle management. To favor pasture and rangeland grass growth, do not overgraze.
Please note that there are some native thistles, which are not noxious plants.
Other Links For Further Information:
http://extension.colostate.edu/topic-areas/natural-resources/musk-thistle-3-102/