Invasive Plant: Tansy

Click on image for full size viewDescription:
Perennial, blooms July-October, height up to 6'

A mature common tansy plant has a yellow flower, without petals, that is about 1/2 inch in diameter and is flat on the top.   The common tansy is a toxic plant.  It doesn't often cause death, but in large amounts, and long-term consumption, it can.  Grows in waste areas, roadsides, and meadows.  They are spread through the entire United States.  The strong, fibrous roots and rhizomes are located near surface and root fragments can sprout.

Control:

• Mechanical – Mowing and hand-pulling will reduce seed production, but root fragments will still sprout. Be sure to wear gloves to avoid absorbing toxins through skin while pulling plant.
• Chemical – Spot-spraying with 2,4-D, Transline, Telar, Milestone & Escort, or Escort is effective but may need to be repeated.

* Tansy has a long history of culinary and medicinal use, but the plant’s toxic properties are cumulative.  Illness, convulsions, and even death can result from consuming or handling this plant.  Toxic to horses and cows.  Sheep and goats however eat the plant with enthusiasm.

Photo Credits: Marsha Watland, BSWCD and Judy Sinclair and USDA
Resources: Botony in a Day by Thomas J. Elpel,   Montana State University Extension by Ron LeCain & Roger Sheley, Carol Estes Mortenson at Leech lake Division of Resource Management, Marsha Watland (BSWCD)-funding National Fish & Wildlife Foundation