At the present rate of infestation, Canada thistle will surpass leafy spurge in total acreage by 2002. The most recent data suggests it already infests more than 900,000 acres. The North Dakota Extension Service and Department of Agriculture has received numerous phone calls from landowners who are concerned with lack of Canada thistle control in neighboring cropland, pasture and CRP lands.
State law requires every citizen to control the spread of noxious weeds on their lands.
If noxious weeds are not properly controlled, complaints should be made to county or city weed boards. Canada thistle acreage in North Dakota is up 300 percent since 1992 with an average of 99,000 acres added every year. It has been declared a noxious weed in almost every state. It is one of the most widespread, tenacious and economically damaging weeds in the U.S. and Canada. Canada thistle principally reproduces by sending out shoots from lateral roots, and can readily regenerate from root fragments less than an inch in length.