Ragwort

Ragwort (Senecio jacobaea) is native biennial which is a food souce for a wide range of insects. It is not usually a significant problem in gardens, but its poisonous qualities can make it a serious weed of paddocks and gardens backing onto fields grazed by horses or cattle.

Common ragwort. Image: RHS
Common ragwort. Image: RHS

Quick facts

Common name Common ragwort
Latin name Senecio jacobaea
Areas affected Waysides, grazing land and uncultivated ground
Main causes Weed poisonous to cattle and horses
Timing Seen from spring to autumn; treat in late spring or autumn

What is ragwort?

Ragworts (Senecio spp.) are found throughout the British Isles in grassland, verges, waste land and negelected or over-grazed pastures. Its flowers are attractive to a wide range of insects including butterflies and moths. The distinctive yellow and black striped caterpillars of the Cinnabar moth are often seen feeding on the foliage. In gardens, ragwort can be a welcome food source for many insects and a cheerful addition to a flower-rich meadow, provided this is not near paddocks grazed by horses and livestock. Learn more about making the most of lawns as a wildlife habitat and ways to help our bees and butterflies;


Bees in your garden

Bees in your garden

Butterflies in your garden

Butterflies in your garden

Lawn and mini-meadow habitats

Lawn and mini-meadow habitats


Ragworts (Senecio spp.) are poisonous weeds of which Senecio jacobaea is the most common. Their seeds are spread by wind and a single plant is capable of producing 50 - 60 000 seeds. It can become a major weed of waste or other uncultivated ground. This page looks at options for gardeners when ragwort is becoming a problem.

Appearance

Ragwort is a tall erect plant to 90cm (3ft) bearing large flat-topped clusters of yellow daisy-like flowers from July to October. It has finely divided leaves with a basal rosette of deeply-cut, toothed leaves.

The plant is usually a biennial (living only two years and flowering in its second year) but damage to the base of the plant can make the plant behave like a perennial (living indefinitely), as new rosettes are formed.

The problem

Ragwort is rarely a problem in gardens but may occur in pony paddocks, railway embankments and areas of unimproved pasture. Cattle and horses are particularly susceptible to poisoning. Cutting, wilting and the treatment with herbicides make ragwort less unpalatable to livestock and poisoning mainly arises from eating contaminated hay.

Common ragwort produces large numbers of seeds which are dispersed by the wind.

Ragwort is covered by the Weeds Act 1959 (which specifies five injurious weeds including common ragwort) and the Ragwort Control Act 2003. For guidance, on good practice and the legal framework for land managers, consult the Code of Practice on How to Prevent the Spread of Ragwort.

Control

First, consider whether this can be done using non-chemical means such as digging out and where this is not feasible, chemical controls may need to be used.

The RHS believes that avoiding pests, diseases and weeds by good practice in cultivation methods, cultivar selection, garden hygiene and encouraging or introducing natural enemies, should be the first line of control. If chemical controls are used, they should be used only in a minimal and highly targeted manner.

Cultural control

Non-chemical options can be used to control and eradiate ragwort. Cutting at the early flower stage reduces seed production. Cut plants can still be a risk to grazing animals, so where animals are present, the cut ragwort should be removed.

Pulling is practical on loose soil. Hoe off seedlings. Dig or fork out larger plants.  

Weedkiller control

The RHS does not support the use of weedkillers and recommends that alternative control methods are used. However, we do note that when gardeners struggle to control plants with cultural methods, regulated weedkillers/pesticides for home gardeners are available for use legally. Garden centres and large retailers selling weedkillers have trained staff who can advise on suitable products for your needs.

Weedkillers suitable for large-scale pasture use are available only to qualified professionals. Contact agricultural contractors to treat paddocks and similar areas (see the National Association of Agricultural Contractors). 

Weeds: non-chemical control

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