Common Tansy

(Tanacetum vulgare)

Family: Asteraceae

Life cycle: Perennial

Roots: Extensive root structure, which make hand pulling almost entirely futile.  Very rhizomatous

Leaves: Alternate, pinnately compound and become smaller toward the top of the stalk.  Leaves are very aromatic when crushed.  Smells mentholated

Flowers:  Dense clusters of daisy like yellow discs that lack petals.

Effective control methods:

Herbicide, mowing

Herbicide works very well to control infestations of common tansy, however, many times patches tend to grow in ditches or along waterways, which makes selection of herbicide very important.

Mowing:  Mowing will reduce the seed bank of common tansy but because this weed also propagates through rhizomes it will not completely control this problem.  Mowing is a great prelude to herbicide application because it removes old, tall stalks and allow herbicide to reach the rosette for better coverage.

Hand-pulling: This method has not been shown to work, though, hand-pulling very small patches and meticulously removing all rhizomes may prove in slowing down growth.  Again, consistency is key.