Common Tansy

Common Tansy is a herbaceous perennial, 30 – 150cm tall. Tansy has foliage that resemble ferns and yellow button-like flowers. Common tansy spreads quickly through rhizomatous root systems and fast seed production. Tansy is found in various locations such as: meadows, riparian areas, along roadsides, ditches, also in managed landscapes.

Tansy reproduces mainly by seeds, but also spreads by rhizomatous root systems. Tansy’s rizomatous root systems cause dense growth patches. Dense patches of tansy can decrease availability of plants for grazing animals. Common Tansy contains a chemical known as Thujone, and is considered to be poisonous to both livestock and humans. Though its poisonous nature, Tansy is considered unpalatable, making it quite rare for livestock or human poisoning. Thujone can also cause skin irritation and contact dermatitis. Wearing gloves and long sleeves can prevent the effects on skin.

Scientific Name: Tanacetum vulgare

Common Name: Common Tansy

Type: Invasive Plant, Noxious Weed

Family: Asteraceae

Control Methods

There are a couple different ways to control Common Tansy. Mechanical controls include: hand pulling, or tools such as trowels or shovels. Make sure to remove as much of the root system as possible. Mowing or string trimming prior to flowering will prevent seeds from dispersing and establishing. Herbicides can also be effective at controlling established plants. Encouraging plants that can outcompete Tansy is also an effective method of controlling the spread of the plant.

Disposal

Tansy should not be combined with other green waste. Notify the attendant when bringing to green waste facilities to see if they have an area where it can be disposed. For green waste facilities put contents into a clear plastic bag. If there is not a location for it to be disposed, contents can be put into a black plastic bag and put it in your garbage bin or take to your local garbage disposal facility.