Colorado State University Weed Science Information:


Herbicide resistant weeds in Colorado

Updated November, 2016. Source: – Colorado

Reading this list: Each weed with herbicide resistant populations in this state is listed. Underneath each species is a list of the unique resistant biotypes of that weed in the state, according to the herbicide group(s) they are resistant to.


  • Group 2 resistance
  • Group 4
  • Group 5
  • Group 9

Redroot pigweed

  • Group 5

Wild oat

  • Group 1