
Tansy (Tanacetum vulgare)
Perennial herbaceous plant, 2-5’ tall, erect, unbranched except for the flower head, stems slightly hairy, woody and purplish red near the ground.
Overview
Tansy is Restricted (Orange counties)
Other names for this plant include:
- Common names: common tansy, golden buttons, garden tansy
- Scientific names: Chrysanthemum vulgare; T. boreale
Ecological threat:
- Invades well-drained or sandy soils in open disturbed areas, roadsides, fields, prairies, pastures, and hedgerows.
- Once established, infestations of common tansy displace native vegetation.
Classification in Wisconsin: Restricted (cultivars 'Aureum' and 'Crispum' are exempt)
Species Assessment Groups (SAG) were assembled to recommend a legal classification for each species considered for NR 40. The recommendation for tansy was based upon this literature review developed by the department.
Identification
Leaves: Alternate, pinnately compound with deeply divided, toothed, fern-like leaflets, 4-10” long and 1½-3” wide. Leaves are strongly aromatic when crushed.
Flowers: Bright yellow, button-like discs up to 0.5" wide, in a flat-topped cluster blooming from July through October.
Fruits & seeds: Seeds are dispersed by wind and water.
Roots: Extensive spreading root system. Tansy regenerates from root fragments.
Similar species: Common tansy should not be confused with Lake Huron tansy (Tanacetum huronense; native), a Wisconsin endangered species which is shorter (16-23”), has fewer and larger flowers, and is found on sandy beaches, lake dunes, and cracks in limestone pavement.
Distribution
Counties in WI where tansy has been reported (as of July 2011). Both vouchered and unvouchered reports included.
Do you have tansy in your county but it isn't shaded on the map? Send us a report.
Control
Mechanical: an be cut or mowed prior to flowering to prevent seed set. Removing the dead vegetation with controlled burns can make the plants easier to target with herbicides.
Chemical: Foliar spray rosettes in spring using dicamba, glyphosate, metsulfuron methyl with a surfactant, 2, 4-D, clopyralid or a mixture of 2, 4-D and clopyralid.
For more information on control techniques, visit the Tansy factsheet [exit DNR] by University of Wisconsin-Extension.
Photos
View tansy pictures in our photo gallery!
Resources
Sources for content:
- Czarapata, Elizabeth; Invasive Plants of the Upper Midwest: an illustrated guide to their identification and control. University of Wisconsin Press. 2005. Pg. 70-72
Links for More Information