{"id":464,"date":"2026-02-11T20:55:38","date_gmt":"2026-02-11T20:55:38","guid":{"rendered":"https:\/\/extension.colostate.edu\/gilpin\/?post_type=resource-cpt&#038;p=464"},"modified":"2026-02-27T23:49:22","modified_gmt":"2026-02-27T23:49:22","slug":"canada-thistle","status":"publish","type":"resource-cpt","link":"https:\/\/extension.colostate.edu\/gilpin\/resource\/canada-thistle\/","title":{"rendered":"Canada Thistle"},"content":{"rendered":"\n<div class=\"wp-block-group wp-block-pattern-longform-content is-vertical is-layout-flex wp-container-core-group-is-layout-fe9cc265 wp-block-group-is-layout-flex\">\n<div class=\"wp-block-group wp-block-pattern-quick-facts has-gray-50-background-color has-background is-vertical is-layout-flex wp-container-core-group-is-layout-fe9cc265 wp-block-group-is-layout-flex\">\n<h3 class=\"wp-block-heading\">Noxious Weed Facts<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Canada thistle is a creeping perennial that spreads by <strong>roots AND seeds<\/strong>, so it can bounce back fast.<\/li>\n\n\n\n<li>Infestations can reduce usable forage because <strong>cattle usually won\u2019t graze near it<\/strong>.<\/li>\n\n\n\n<li><strong>Pull early and often<\/strong> (monthly for years) and <strong>bag\/dispose flower heads<\/strong> to prevent seed. Best results come from <strong>mechanical and chemical control<\/strong> together.<\/li>\n<\/ul>\n<\/div>\n\n\n\n<div class=\"wp-block-group is-layout-constrained wp-block-group-is-layout-constrained\">\n<p>This creeping perennial reproduces from vegetative buds in its root system and from seed. It infests crops, pastures, rangeland, roadsides and non-crop areas. <\/p>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-28f84493 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:60%\">\n<p>Canada thistle reduces forage in pastures and rangeland because cattle typically will not graze near infestations.<\/p>\n\n\n\n<p><strong>Identification<\/strong>: Grows 2-4&#8242; tall. Leaves are oblong, spiny, bright green, and slightly hairy on undersurface. Flowers occur in small clusters of 1 to 5 flowers. They are about 1 cm in diameter, tubular-shaped, and vary from white to purple in color.<\/p>\n\n\n\n<p><strong>Treatment<\/strong>: Hand pull before thistle flowers\/should be done monthly over several years; do not allow plant to go to seed (bag\/dispose of any flower heads). Combining mechanical and chemical control methods is the best form of Canada thistle management.<\/p>\n\n\n\n<p>Please note that some\u00a0<strong><a href=\"https:\/\/extension.colostate.edu\/gilpin\/resources\/\" data-type=\"page\" data-id=\"444\">native thistles<\/a><\/strong> are not noxious plants.<\/p>\n\n\n\n<p><strong><a href=\"https:\/\/extension.colostate.edu\/gilpin\/contact\/\">Contact Gilpin County Extension<\/a><\/strong> for herbicide recommendations.<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:40%\">\n<div class=\"wp-block-group is-layout-constrained wp-container-core-group-is-layout-80fb368b wp-block-group-is-layout-constrained\" style=\"padding-top:var(--wp--preset--spacing--30);padding-right:var(--wp--preset--spacing--30);padding-bottom:var(--wp--preset--spacing--30);padding-left:var(--wp--preset--spacing--30)\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"338\" height=\"451\" src=\"https:\/\/extension.colostate.edu\/gilpin\/wp-content\/uploads\/sites\/34\/2026\/02\/Canada-Thistle.jpg\" alt=\"Canada thistle flower\" class=\"wp-image-549\" srcset=\"https:\/\/extension.colostate.edu\/gilpin\/wp-content\/uploads\/sites\/34\/2026\/02\/Canada-Thistle.jpg 338w, https:\/\/extension.colostate.edu\/gilpin\/wp-content\/uploads\/sites\/34\/2026\/02\/Canada-Thistle.jpg?resize=225,300 225w\" sizes=\"auto, (max-width: 338px) 100vw, 338px\" \/><\/figure>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n<hr aria-hidden=\"true\" class=\"wp-block-separator has-alpha-channel-opacity is-style-simple\"\/>\n<\/div>\n\n\n\n<div class=\"wp-block-group is-layout-constrained wp-block-group-is-layout-constrained\">\n<h4 class=\"wp-block-heading\">Additional Resources<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong><a href=\"https:\/\/extension.colostate.edu\/resource\/canada-thistle\/\">Canada Thistle | CSU Extension Fact Sheet<\/a><\/strong><\/li>\n<\/ul>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>Noxious Weed Facts This creeping perennial reproduces from vegetative buds in its root system and from seed. It infests crops, pastures, rangeland, roadsides and non-crop areas. Canada&#8230;<\/p>\n","protected":false},"author":45,"featured_media":0,"parent":0,"menu_order":0,"template":"","meta":{"_acf_changed":false,"footnotes":""},"area_tax":[],"county_tax":[127],"global-category_tax":[165,167,179],"global-offering_tax":[],"global-sub-category_tax":[261,287,325,360],"global-topic_tax":[375],"region_tax":[385],"resource-type_tax":[388],"class_list":["post-464","resource-cpt","type-resource-cpt","status-publish","hentry"],"pp_statuses_selecting_workflow":false,"pp_workflow_action":"current","pp_status_selection":"publish","pp_post_mime_type":"","acf":[],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/resource-cpt\/464","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/resource-cpt"}],"about":[{"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/types\/resource-cpt"}],"author":[{"embeddable":true,"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/users\/45"}],"version-history":[{"count":7,"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/resource-cpt\/464\/revisions"}],"predecessor-version":[{"id":658,"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/resource-cpt\/464\/revisions\/658"}],"wp:attachment":[{"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/media?parent=464"}],"wp:term":[{"taxonomy":"area_tax","embeddable":true,"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/area_tax?post=464"},{"taxonomy":"county_tax","embeddable":true,"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/county_tax?post=464"},{"taxonomy":"global-category_tax","embeddable":true,"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/global-category_tax?post=464"},{"taxonomy":"global-offering_tax","embeddable":true,"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/global-offering_tax?post=464"},{"taxonomy":"global-sub-category_tax","embeddable":true,"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/global-sub-category_tax?post=464"},{"taxonomy":"global-topic_tax","embeddable":true,"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/global-topic_tax?post=464"},{"taxonomy":"region_tax","embeddable":true,"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/region_tax?post=464"},{"taxonomy":"resource-type_tax","embeddable":true,"href":"https:\/\/extension.colostate.edu\/gilpin\/wp-json\/wp\/v2\/resource-type_tax?post=464"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}