Tansy Ragwort (Jacobaea vulgaris syn. Senecio jacobaea)
Factsheets
Description
Short-lived perennial flower between 20-120 cm tall. Flowers are yellow and daisy-like, arranged in a dense, flat-topped cluster at the top of a purplish stem. The leaves are highly lobed and ruffled.
Habitat
Tansy Ragwort is native to Europe, Asia, and Siberia. On Galiano Island, it is generally found in sunny, disturbed areas, such as pastureland, grasslands, and roadsides.
Impact
Tansy ragwort is poisonous to people and animals, and can cause potentially fatal liver damage if consumed. Alkaloids in the plant will taint the honey of bees, making it generally too bitter and off-colour to sell and consume. Tansy ragwort spreads rapidly: one plant can produce 150,000 seeds, and the seeds can persist in the soil for up to 15 years.
Management
Hand-pull plants that are between knee-height and hip-height, ideally prior to flowering (usually end of June). Pull from near the base to ensure that as much of the root is removed as possible and avoid re-sprouting. When pulling plants that are blooming, it is recommended to cut, bag, and burn flower heads. Younger plants can be ignored – the roots fragment much more easily than older plants during removal, and may even increase the rate of spread. Pulled plants without flowers can be discarded in the forest in shady areas, provided they are located where they will not result in a fire hazard.
Our Experience
This species is a relatively recent introduction to Galiano Island, and has rapidly formed small populations along roadways and in disturbed areas across the island. New populations are very easy to control as long as they are removed in a timely manner; larger populations take several years of persistent annual removal to eliminate. Tansy ragwort should be removed wherever it occurs.