There are several different species of ragwort (Senecio spp) that occur in Britain, all of which are potentially poisonous to livestock, but the main species that causes most concern is the common ragwort, Senecio jacobaea.
Common ragwort is a native, biennial plant that naturally occurs in our grasslands. A single plant can produce many thousands of seeds that are dispersed by wind, although very few travel beyond 5m of the parent. The seed readily germinates in open soil.
The problem with common ragwort
The problem with common ragwort is that it is a recognized injurious plant because it is toxic to livestock, horses being particularly susceptible and is frequently fatal to them. Though animals tend to avoid ragwort whilst growing, it can easily be ingested if hidden in fodder such as hay. The toxins cause cirrhosis of the animal’s liver and the damage is irreversible. For this reason, common ragwort is one of the plants listed in the ‘Weeds Act’ 1959 where landowners are required to control the spread of ragwort from their land. Also, a ‘Code of Practice on how to prevent the Spread of Ragwort’ was published by Defra in 2004. www.defra.gov.uk/publications/files/pb9840-cop-ragwort.pdf
On the other hand, there are wildlife benefits of the plant that should not be overlooked. There are several species of insects that rely on ragwort in their life cycle, probably the best known being the yellow and black hooped caterpillar of the Cinnabar moth. It is a useful nectar plant for many butterflies and there are 30 species of other invertebrates that are wholly dependent on ragwort of which 10 are scarce or rare. Also, control methods can accidentally target very similar plant species to ragwort that are a lot more scarce such as goldenrod and species of St. John’s wort.
Dorset Wildlife Trust therefore takes a balanced view and recognises that ragwort does need controlling but not eradication and it takes all reasonable actions to do this on their nature reserves, in line with Defra’s Code of Practice. In most cases, good pasture management suffices but there are times when situations beyond our control can cause ragwort to grow abundantly, and this appears to be the case this year (2012) in many parts of west Dorset and not just on nature reserves.
In situations where ragwort becomes established, the Trust usually controls by pulling and removing off-site, though in some years when there is heavy infestation this can be very labour intensive. As a last resort topping of flowering plants is undertaken where feasible to prevent spread of seed, but this can also present its own set of problems such as removal of livestock from these areas.
This summer 2012, both these methods have had to be used at the South Poorton nature reserve in west Dorset. Over 40 man days were spent pulling ragwort with great help and support from volunteers, and some areas topped, only leaving a relatively small amount on the more inaccessible areas of the reserve.
For more information and a leaflet about managing common ragwort, please visit: www.plantlife.org.uk/uploads/documents/RAGWORT_leaflet_FINAL.pdf
Head of Land Management
Dorset Wildlife Trust