Identify & Control: Common Tansy (Tanacetum vulgare)

Introduced in North America from Europe in the 1600s, Common Tansy has bright yellow, aromatic flowers and has been used medicinally—despite it being toxic to humans and animals if consumed in large quantities—and as an insect repellent. It forms dense stands that can grow up to 1.5 metres tall, flourishes in full sun, well-drained soil, and reproduces using underground horizontal roots and seeds. It can outcompete and displace native plants, reducing natural biodiversity and available forage for livestock and wildlife¹. Common Tansy is most commonly found on stream banks, and along roadsides and other disturbed soil sites.²