Onopordum acanthium - Asteraceae Family - Biennial
Monitor and destroy new plants before seed production.
Hand pulling, digging, cutting, mowing and tilling.
Biological control agents, livestock grazing, and revegetation practices.
Selective herbicides based on the plant and the specific location. Check our weed fact sheets for specific control information.
Scotch thistle: flower
Scotch thistle: infestation
Scotch thistle: rosettes
Scotch thistle: foliage
Scotch thistle: rosette
Scotch thistle: seeds
J.M., G.B. Kyser et al. (2013). Weed
Control in Natural Areas in the Western United States [PDF file]. Weed
Research and Information Center, University of California. Retrieved from https://wric.ucdavis.edu/information/natural%20areas/wr_O/Onopordum.pdf
(2016, September 1). Managing Scotch
thistle on rangeland and natural areas. Retrieved from https://www.techlinenews.com/articles/2016/managing-scotch-thistle-on-rangeland-and-natural-areas
Species Compendium. (2017, November 22). Onopordum
acanthium (scotch thistle). Retrieved from https://www.cabi.org/isc/datasheet/37456
& Johnson, W. Managing Scotch Thistle
[PDF file]. Retrieved from https://www.unce.unr.edu/publications/files/nr/2002/FS0257.pdf
States Department of Agriculture. (2014, September). Field Guide for Managing Annual and Biennial Invasive Thistles in the
Southwest [PDF file]. Retrieved from https://www.fs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb5410130.pdf