Laserfiche WebLink
Canada Thistle Identification and Management <br /> its root system, and quickly form <br /> . tyyiy<c dense stands. Each fragmented <br /> piece of root, 0.25 inch or larger, is W <br /> capable of forming new plants. The { <br /> 0", key to controlling Canada thistle is <br /> j to eliminate seed production and to <br /> reduce the plant's nutrient reserves <br /> in its root system through persistent, <br /> long-term management. s <br /> F <br /> Canada thistle is one of the mostf1. <br /> troublesome noxious weeds in <br /> n. , <br /> the U.S. It can infest diverse land <br /> =` types, ranging from roadsides, ditch <br /> banks, riparian zones, meadows, R <br /> Canada thistle (Cirsium arvense) pastures, irrigated cropland, to the <br /> is a non-native, deep-rooted most productive dryland cropland. <br /> perennial that spreads by seeds and Large infestations significantly reduce <br /> aggressive creeping, horizontal roots crop and cattle forage production . <br /> called rhizomes. Canada thistle can and native plant species. It is a host <br /> grow 2 to 4 feet in height. The leaves plant to several agricultural pests and <br /> are oblong, spiny, bright green, and diseases. Canada thistle prefers moist , <br /> slightly hairy on the undersurface. soils, but it can be found in a variety <br /> Unlike other noxious biennial thistles of soil types. It has been found at <br /> which have a solitary flower at the elevations up to 12,000 feet. x: n <br /> end of each stem, Canada thistle <br /> flowers occur in small clusters of 1 ffective Canada thistle control <br /> to 5 flowers. They are about 1 cm in Erequires a combination of <br /> diameter,tubular shaped, and vary methods. Prevention is the most <br /> from white to purple in color. important strategy. Maintain healthy S� <br /> pastures and rangelands, and <br /> Canada thistle emerges from continually monitor your property for <br /> its root system from late April new infestations. Established plants <br /> through May. It flowers in late spring need to be continually stressed. ILA <br /> and throughout the summer. It Management options become limited r� <br /> produces about 1,000 to 1,500 seeds once plants begin to produce seeds. VU <br /> per plant that can be wind dispersed. Details on the back of this sheet can �'JU <br /> Seeds survive in the soil for up to 20 help to create a management plan <br /> years. Additionally, Canada thistle compatible with your site ecology. n <br /> reproduces vegetatively through <br /> anada thistle is I Key D Points <br /> 2013 Quarter Quad Survey designated as a "List <br /> B" species as described 1.Cluster . <br /> Canada Thistle °u:�� ;,�•°� °rr "''="°'r-""" in the Colorado Noxious opurple <br /> p <br /> Crsrum amnse •�, <br /> Weed Act. It is required flowers <br /> -' to be either eliminated, stern. <br /> } contained or suppressed 2. Floral bracts <br /> depending on the local arespineless. <br /> infestations. For moreflowers <br /> ti information visit www. that are I CrIl III <br /> VP IKt'� �L_ colorado.gov/ag/weeds <br /> and click on the Noxious 4. Perennial, <br /> Weed Program link or rhizornatous <br /> call the State Weed plant with <br /> Coordinator at the spiny, oblong, <br /> ,< Colorado Department ofgreen leaves. <br /> Agriculture, Conservation <br /> Services Division, <br /> ._.. �. .... (303) 869-9030. <br />