Common Tansy

Description: COMMON TANSY — Tanacetum vulgare L. Asteraceae — (Sunflower family) Common tansy is a native of Europe and came to the U.S. as an ornamental and for medicinal purposes. It is an aromatic perennial and is generally found along roadsides, waste areas, stream banks and in pastures throughout most of the U.S. and Canada. It reproduces from seeds and rootstalks. Leaves are alternate, deeply divided into numerous, narrow toothed segments. Yellow flower heads, ¼ to ½ inch across, are numerous in flat-topped dense clusters. Seeds are yellowish-brown with short 5-toothed crowns. Common tansy is sometimes mistaken for Tansy ragwort. Non-Standard name: garden tansy. Growth Habit: Perennial, bushy upright, stems are from 1 ½ to 6 feet tall. Leaves: Divided into individual leaflets, serrated on the margins. Stem: Many stems, often purplish-red in color. Flower: Flower heads contain button-like flowers without petals ¼ to ½ inch across and growing in dense, flat topped clusters. Roots: Rootstalks. Seeds: Yellowish-brown with short, 5-toothed crowns. (Courtesy of Weeds of the West) CONTROL STRATEGIES: Common tansy is fairly herbicide resistant. Repeat treatments are frequently needed regardless of choice of herbicide and rate. It appears to respond well to cultivation as it is seldom seen on crop land while it dominates adjacent fence lines and irrigation ditches. The Cooperative Extension Services Herbicide Manual suggests at tank mix of 1 to 2 quarts of Clarity plus one quart of Tordon 22K. In Fremont County, we have seen excellent control from Telar at one ounce per acre when using a good surfactant to help the herbicide get into the leaves. To learn about biological control agents for Common Tansy visit this link. Infestation Map: Click map for larger view

450 N. 2nd Street Lander, WY 82520 / 307-332-1052 1446 Cowboy Lane Riverton, WY 82501 / 307-856-2192 fcwp@wyoming.com