Ragwort has become a widespread issue for horse and donkey owners, as the plant, which commonly thrives on wasteland and road verges, continues to spread to grazing land. Find out how to keep your donkeys safe from this toxic plant.

Ragwort contains toxic compounds that cause liver damage to equines and other livestock animals, and in many instances can be fatal.

The yellow flowering plant acts as a cumulative poison, and can pose a real danger whether eaten in large quantities in a short period or in small amounts over a longer period of time. While horses and donkeys may instinctively avoid eating ragwort, this is not always the case, particularly when grazing is sparse. It is just as toxic when cut and dried, since this is when the plant loses its bitter taste and will be even more palatable. Owners should be very aware of this plant both in pasture and baled hay/haylage.

There are several methods for removing it and ideally this should be done in spring and summer before ragwort is able to seed. If pulled by hand, gloves should be worn at all stages to ensure the handler’s health and safety.

Ragwort at a glance

Common name: Common ragwort
Latin name: Senecio jacobaea
Usually seen: In paddocks and pasture land, particularly where the land is overgrazed, as well as on road verges and wasteland
When to act: Spring and summer
Need to know: This plant is poisonous to equines and other grazing animals

What is ragwort?

Common ragwort (Senecio jacobaea) is a poisonous plant that is becoming increasingly common in Britain. It is regularly seen growing along roadsides, on wasteground and in areas of poor land management, spreading easily onto pastures and farms. Ragwort is a wild flower native to Eurasia but now found throughout the world. It is sometimes known as benweed in Ireland and in parts of the USA it is generally known as tansy ragwort, or tansyweed, although its resemblance to the true tansy is superficial.

How does ragwort affect livestock and how does poisoning occur?

Equines (horses, ponies, donkeys and mules) and bovines (cattle) are more susceptible to ragwort poisoning than other livestock; with young animals being more prone than older ones. Poisoning can occur at any time of the year, generally having a cumulative effect. A very small intake over a long period of time can be just as damaging as a large intake over a short period. The poison itself does not accumulate in the body, but over time more liver cells are destroyed, eventually resulting in liver failure. Liver damage can be very subtle, and may go by unnoticed for months/years, even decades before it is detected. Liver failure occurs when approximately 80% of the liver is damaged. Despite its bitter taste, equines will eat ragwort, especially during times of sparsity, overstocking or poor land management. Ragwort becomes more palatable when dried in hay, haylage or dried grass and can be difficult to distinguish from other plant species in the bale. For this reason it is important to split and examine every bale fed to your animals for any evidence of ragwort and always discard any suspicious bales.

What are the clinical signs of ragwort poisoning?

Ragwort poisoning is rarely identified before the liver has undergone irreversible damage and symptoms will only become apparent at this late stage. There are no early warning signs.

Symptoms first seen may include:

  • Depression
  • Loss of condition/poor appetite
  • Diarrhoea or constipation
  • Photosensitivity (sunburn) affecting unpigmented (pink) skin
  • May have a jaundiced (yellow) appearance (mucous membranes such as gums and the conjunctiva or soft tissue surrounding the eyeball).

Progressing to more terminal signs including:

  • Strange nervous behaviours
  • Restless/aimless and uncoordinated movements/repetitive circling
  • May appear to be blind
  • Head pressing against solid objects
  • Abnormal gait and stance
  • Haemorrhage
  • Loss of consciousness.

Once clinical signs are seen it is too late for treatment in the vast majority of cases as the liver will be irreparably damaged. A blood sample can be taken to confirm liver failure, although there is no diagnostic test available to confirm the causal factor.

How can I identify ragwort?

Flowering ragwort can be identified by its mass of bright sunshine yellow daisy-like flowers measuring 1-2 cm across. A mature plant usually stands anywhere between 30-100 cm tall, but can sometimes reach 2 metres in height. The lower leaves, stems and roots may have a purple/red tinge. It’s important to note that it’s harder to identify young plants and those gone to seed.

Ragwort is usually biennial, taking two years to reach flowering and maturity, although in some circumstances it can flower in the first year of growth. Seedlings can appear from autumn onwards - the first true leaves, 10-12 mm in length, are hairless and have a characteristic spade shaped blade with a smooth edge. As the plant grows, the leaves produced show a gradual increase in the waviness, typical of the older ragwort plants. Rosettes can be found from early spring onwards and have a circular cluster of leaves with a ragged appearance, usually deep green on top and covered in a cottony down underneath. The rootstock, basal leaf stalks and lower parts of the stem may have a purplish/ red colour. (If biennial it will over-winter as a rosette and during the second year send up a single leafy stem that will produce numerous flower heads).

Flowering occurs from May to late October. Ragwort produces masses of tiny seeds from each flower. The seed head itself has a similar appearance to the commonly recognised dandelion. Once seeds are produced and dispersed in the wind the plant dies back, creating a gap suitable for immediate colonisation by seedlings.

The provisions of the Weeds Act only apply to common ragwort (Senecio jacobaea). Other species of ragwort, eg marsh ragwort (Senecio aquaticus), hoary ragwort (Senecio erucifolius) and Oxford ragwort (Senecio squalidus) are less common but may still need to be controlled as they may be equally toxic to horses or other livestock. Some species of ragwort are relatively rare, such as fen ragwort (Senecio paludosus), which is a protected species and has been reintroduced into several sites in England. Welsh ragwort (Senecio cambrensis) (also sometimes known as Welsh groundsel) is restricted entirely to North Wales.

Not to be confused with ragwort there are a number of lookalikes, including tansy and St John's wort.

Ragwort in flower
Ragwort floret
Cinnabar caterpillars on ragwort

How can I control ragwort on my land?

Implementing an effective control strategy is the only way to avoid the spread of ragwort and subsequent poisoning. Preventing harmful weeds and invasive non-native plants spreading guide, available from the Department of Environment, Food and Rural Affairs (DEFRA), can provide further help. To eliminate the danger to your animals it is important to remove all potential sources of poisoning as quickly as possible and a control strategy must be employed.

The chosen method should be the least damaging to the environment and human health while still being an effective method of control. Consider removing your animals from any affected grazing to allow for proper removal of the plants. The benefits of ragwort control methods are short lived unless the pasture is well-managed, or re-infestation will inevitably result. Over and under grazing creates open patches where ragwort can readily establish itself.

Detection at an early stage of infestation will be easier, quicker and more economical to treat when compared with eradication of a well-established infestation.

The following techniques can be used singly or in combination to reduce, control or eliminate ragwort.

Pulling/digging

Removal needs to be done before flowering has completed and is more easily achieved when the plant is immature (seedling or rosette) or after heavy rainfall when the ground is soft. As ragwort is a biennial, this method will need to be employed for at least two years and, if the pasture has a history of ragwort infestation, this needs to be carried out annually due to the remaining seeds in the soil. It is important to remove as much of the root as possible, since ragwort can re-generate from a root as small as 1 cm. Rock salt, bought from any agricultural merchants, poured into the hole after digging helps to kill the remaining roots. Tools can be purchased for the job, such as the Lazy Dog Tool or Rag Fork. It’s also important to always cover arms and legs by wearing gloves and a facemask to avoid the inhalation of ragwort pollen, or other airborne particles.

The pulling of ragwort by machine can be more appropriate for large areas of ragwort but there has to be a significant height difference between the ragwort and other plants.

Cutting

Cutting at the early flowering stage reduces seed production. It is acceptable in an emergency situation but generally not recommended since it encourages more vigorous re-growth.

Herbicides

Herbicides can be an effective method of ragwort control if used at the appropriate time of year. Careful consideration should be given to ensure the most suitable product and method is used to limit the grazing and environmental implications. For advice on the choice of herbicides and suitable application technique, seek advice from a BASIS trained agronomist by contacting your local agrochemical distributor. Users must follow both product label advice and codes of practice to ensure that the product is used safely and effectively.

Please note that two common label statements on the products likely to be used for ragwort control are:

  • Exclude livestock from the treated area until specified
  • Palatability of treated ragwort plants is increased therefore removal of all dead plants is essential.

Alternative herbicides

Alternatively, there is a range of natural non-toxic herbicides now on the market, such as Barrier H produced by Barrier BioTech Limited, which is a fully licensed agricultural herbicide.

Disposing of ragwort

Disposal options will depend on the amount of ragwort and whether your land comes under domestic or non-domestic classification, for example equestrian premises. Ideally, it should be disposed of (see the above DEFRA guide for further advice). For small amounts of ragwort the simplest method is to burn the wilted or dead plants (check with your local authority if this is permissible). Do not leave the ragwort where animals can access it as they may eat it.

As ragwort is able to seed, even after removal from the ground, it should be placed into an enclosed container or secured bags (this must be done if it is being transported or moved). Using paper sacks which can be burned will not only prevent seed dispersal but also reduce handling requirements.

Other disposal methods include: rotting down, composting, incineration and landfill.

What can I do if my land is being threatened by ragwort from an external source?

Under the Weeds Act 1959 and The Ragwort Control Act 2003 (England and Wales only), the occupier of the land is responsible for controlling and removing ragwort. If you are concerned about the risk of ragwort spreading onto your land, DEFRA advises that you first try to seek a solution with the occupier of the infested area. However it is expected that all individuals involved should take collective responsibility for ensuring a satisfactory outcome in which the control of ragwort is achieved. Should you be unsuccessful, a Weed Act form would then need to be completed through DEFRA.

There are three risk categories, which can be used as guidelines for assessing the risk posed by ragwort:

  • High risk: ragwort is present and flowering/seeding within 50 m of land used for grazing by horses and other animals or land used for feed/forage production
  • Medium risk: ragwort is present within 50 m to 100 m of land used for grazing by horses and other animals or land used for feed/forage production
  • Low risk: ragwort or the land on which it is present is more than 100 m from land used for grazing by horses and other animals or land used for feed/forage production.

Useful contacts

A control policy should involve collaboration with neighbours/neighbouring agencies to ensure the best possible outcome.

Useful literature

The following publications are available from DEFRA:

  • Code of Practice on how to prevent the spread of ragwort (June 2004)
  • Injurious Weeds and the Weeds Act 1959
  • Ragwort Control Act
  • Guidance on the disposal options for common ragwort.

Other useful contacts

Ecological importance

One final thought. Although ragwort must always be considered a potential poison, in areas where there are no livestock, or neighbouring farms it may be acceptable to leave ragwort untreated due to its ecological importance (see government guidance on how to identify areas of medium to high risk). Ragwort is an attractive plant to many insects and for some rare species ragwort is an exclusive food source and as such has an important role in maintaining the country's biodiversity.

Ragwort is a valuable source of food for the cinnabar moth (black and yellow striped caterpillars).

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