Laserfiche WebLink
Rangeland -Pasture Recommendations <br />Canada thistle Identification and <br />Management <br />Canada thistle (Cirsiuin arvense) is a non-native deep-rooted perennial that <br />spreads by steeds and aggressive, creeping horizontal roots (rhizomes). Canada <br />thistle can grow 2 to 5 feet in height. The leaves are oblong, spiny, bright green in <br />color, and are only slightly hairy on the undersurface. Flowers occur in small <br />clusters that form on the ends of branches. They are about 1 cm in diameter, <br />tubular shaped, and vary from white to purple in color with a strong vanilla <br />scent (female flowers). <br />Canada thistle emerges from its root system from Iate April through May. <br />It begins to flower in late spring to early summer with increase in day length. <br />Canada thistle only produces about 1,000 to 1,500 seeds per plant. Typically, it <br />reproduces vegetatively through a creeping root system, and can quickly form <br />dense stands. Every piece of root, from 1/2to 1 inch in length, is capable of <br />forming new plants. The key to controlling Canada thistle is to eliminate seed <br />production and also to reduce the plant's nutrient reserves in its root system <br />through persistent, long-term management. <br />Canada thistle is one of the most feared noxious weeds in the U.S. as it can <br />infest many land types, from roadsides, ditch banks, riparian zones, pastures, <br />irrigated cropland, to the most productive dryIand cropland. Forage production <br />is severely reduced because cattle will not graze near infestations. <br />Combining control methods for Canada thistle is imperative. The weed <br />needs to be continually stressed, forcing it to exhaust root nutrient stores and <br />eventually die. Of all control methods, prevention is most important. Maintain <br />healthy pastures and rangeland and continually monitor your property for new <br />infestations. <br />On the backside of this sheet are Canada thistle management <br />recommendations. If you have any questions, please contact the Weld County <br />Public Works Dept., Weed Division at (970) 3046496 ext. 3770. Please visit our <br />website at www.weldweeds.org <br />