Ragwort is a highly poisonous plant when eaten and posses a particular threat to horses. Under the Noxious Weed Act local authorities and landowners are legally responsible for ensuring that the land within their control is clear of ragwort: Unfortunately due to lack of enforcement this is not the reality. Therefore as a responsible horse owner you must ensure that all ragwort plants are removed from grazing paddocks.
Ragwort is a biennial plant which means that it grows from seed but remains in the rosette stage during the first growing season. In the second season, the familiar yellow flowers appear. The seeds are produced and then shed. Once the plant has flowered, which normally occurs in late summer, most plants will die off. However if the flower stem is cut ragwort is capable of becoming a short lived perennial (4-5 years).
How to identify ragwort
Knowing how to identify ragwort is essential if you want to eradicate it from your paddocks. Below are some photos of ragwort during different stages of its life cycle.
Germination takes places mainly in the autumn but also in spring. Ragwort tends to favour undisturbed land. It thrives on a wide range of soils, but competes best on lighter free draining soils where fertility is reasonably high and grazing not intensive. Cultivated land rarely has any ragwort growth.
Reproduction & dispersal
Each ragwort plant can produce up to 200,000 seeds over a 4-6 week period from July to September. The majority of seeds are dispersed by wind, but can also be carried by water, in animals coats, on the soles of muddy boots and hooves and on farm machinery. Although seed dispersal has the potential to reach a wide area most seeds fall within 5 metres of the parent plant. The seeds can remain viable for 5-20 years depending on soil conditions. Seed is the principle method of spreading this weed, but root fragments are also capable of reproduction. This is the problem.
The control of ragwort
The only way to safeguard against loss from ragwort poisoning is to eradicate the weed either by digging, pulling, ploughing, cutting or spraying.
Digging – a labour intensive method. Although this will remove the plant immediately you cannot be sure that it won’t return. Ragwort is able to regenerate itself from the smallest root fragment that is left behind. A specialist fork can be purchased from retailers to help remove ragwort roots.
Pulling – again this is a labour intensive method for removing ragwort and is recommended where infestation is not severe. Ideally plants should be pulled when the ground is soft such as after heavy rainfall. The plant is also harmful to humans, so wear protective gloves and clothing when handling it. Ragwort should be removed before it flowers, but if this is not possible use a face mask to avoid inhaling the pollen. If you do come into contact with the plant, thoroughly wash the area in warm, soapy water. Pulled plants should be removed and destroyed. As the seedling and rosette stages are not usually removed by hand pulling, the operation should be repeated for two consecutive years. The downside of pulling ragwort by hand is that the roots often break and leave ends in the ground which are able to regenerate. Also seedlings will remain in the surrounding soil.
Ploughing – this method is ideal for infested paddocks but not practical for many horse owners. You need to follow up with a 3 or 4 year rotation of arable cropping.
Cutting – another method that is not generally suitable for horse owners as cut plants need to be collected and destroyed to prevent the risk of poisoning and further seed formation. Cutting should be done before the plant goes to seed. The advantage of cutting is that it will prevent further dispersal of newly formed seedlings. The disadvantage is that this method must be carried out over a number of years. Also cutting will damage the plant base and may cause the plant to change its habit from biennial to perennial. This means it will return year after year, and not die at the end of its 2nd year
Chemical control – by far the easiest and most effective way to treat widespread infestation of ragwort is to spray your paddocks with the appropriate herbicide. It is essential that paddocks are rested for the recommended time after spraying. Paddocks should be sprayed on a dry day (or during a period of several hours without rain) to ensure that the poison is able to work across the leaf. Otherwise the spray will be washed away. Herbicides work best on ragwort in the rosette stage. Late autumn (mid September – mid November) or early spring (February – mid March) are recommended periods for spraying ragwort, with an appropriate herbicide.
Horses must be kept off the paddocks once it has been sprayed as ragwort will remain just as poisonous as it was in its untreated sate. Ragwort becomes more palatable after spraying as it looses it bitter taste when it starts to wilt and die. A period of 2-3 weeks rest is advised. The plant should then be dug up and removed. If let to rot down naturally a period of 6-10 weeks rest should be allowed. To ensure that all newly emerging seedlings are treated spraying should be done continually for at least 2 years.
There is no ideal method for controlling ragwort but there is no doubt that ragwort kills so keeping your paddocks and grazing areas clear is vital.