Proper identification of thistles along with timely decisions about their control is essential. "When thistles do appear, they should immediately be destroyed by applying herbicide before they are 6 inches tall." -OSU Extension
Oklahoma Cooperative Extension Service's Thistle Identification
Check out the Kansas Department of Agriculture's Plant Protection and Weed Control presentation.
Noxious and Invasive Weeds in Kansas
For more information about invasive thistles, check out this information from the USDA.
Field Guide for Managing Annual and Biennial Invasive Thistles in the Southwest
"For those looking for solutions regarding thistle in your pastures! The ideal time for thistle spraying is now. Once the thistle has started blooming, a reactionary treatment will be required. This treatment isn’t as effective due to the later timing. If you know your pasture has thistles and you’re looking to start controlling them, please contact your local Tyree Ag salesman or call the office so that you can be directed to one. Thanks, as always, for your consideration and business!"
Thanks,
Erik Ellis
KP
