Common Ragwort (Senecio jacobaea) is a native species and so therefore not strictly an invasive species, however it is convenient to deal with it in this section as it shares many of the problems of the invasives.
Like invasive species it is best targeted as a specific problem. It is spread throughout the UK and has become a particular problem in transport corridors where it’s uncontrolled spread has led to a number of high profile campaigns by the British Horse Society.
Common Ragwort is a biennial plant, meaning it completes it’s lifecycle over 2 years, growing from seed to rosette in the first year and rosette to flowering in the second.
Flowering Ragwort is an all too familiar site on the UK transport infrastructure from July through to October but the plant is best tackled when it is less visible at the rosette stage.
Many areas have proactive ragwort strategies in place that keep the plant in check but this is another plant that thrives on neglect.
Ragwort plants contain Pyrolizidine Alkaloids (PAs) which are highly toxic to grazing animals particularly horses.
These PAs cause irreversible liver damage and the effect is cumulative so it can build up over a number of years. It is estimated that Ragwort poisoning is responsible for 2000-6000 horse deaths per year.
Recent research has suggested that Humans are also vulnerable to PA poisoning, PAs can be absorbed through the skin so plants should not be handled with bare hands and the pollen also contains PAs which can be inhaled which is also to be avoided.
Common Ragwort is scheduled under The Weeds Act 1959 and The Ragwort Control Act 2003, the later yielding a Code of Practice for Controlling Ragwort and a Code of Practice for Disposing of Ragwort. Copies of this legislation are available fromDEFRA’s mini-site on Common Ragwort .