The presence of ragwort has become much more visible in recent weeks, with the plant in full bloom and displaying its characteristic yellow flowers. This has sparked numerous queries regarding with whom responsibility lies for controlling ragwort.

Responsibility for controlling ragwort in fields lies with the landowner or the manager of the lands in which the plant is present.

The National Roads Authority (NRA) previously listed relevant local authorities as being responsible for controlling non-invasive plants in areas such as road verges, landscaped areas or public amenities.

The NRA merged with the Railway procurement Agency to establish Transport Infrastructure Ireland with little in the way of direct management for ragwort listed on their website.

Noxious weeds

The Department of Agriculture’s online information portal for the control of noxious weeds contains a downloadable form for reporting the presence of noxious weeds to the following email address: noxiousweedsreport@agriculture.gov.ie.

As the plant is a noxious weed, farmers are obliged to take necessary steps to control its presence and are subject to fines for failing to control the noxious weed. It is therefore not surprising that there is anger at a failure to control noxious weeds in roadside verges and public places.

Regenerating potential

The ragwort plant has huge potential to regenerate and spread from year to year. The Department’s information leaflet states that seed is the principle method of spreading this weed, but root fragments are also capable of reproduction.

It lists that each plant produces 50,000-200,000 seeds over a four- to six-week period (July-Sept) and that ragwort produces feathery type seeds that are dispersed by wind, water, animals, hay and farm machinery. The majority of seeds are dispersed by wind but mainly fall within 5m of the parent plant. Worryingly, seeds can remain viable for 5-20 years depending on soil conditions. Many farmers see a value in removing the plant from roadside verges adjoining their fields to prevent its spread.

Toxic to animals

The plant is highly poisonous and toxic to cattle, horses, deer, goats, pigs and chickens, while sheep are less affected.

Cattle generally do not graze the plant in its vegetative state (unless very tight on grass), but, once cut, the plant releases sugars which make it much more attractive to grazing animals. Therefore it is important to remove the plant in advance of topping or post-topping. It also presents a large risk where it is contained in hay or silage, therefore control options must take this into account.

Control options

The best option at present to control ragwort is pulling by hand where its presence is sparse. The Department advises: “Pulling by hand is recommended where infestation is not severe and labour is available. Pulling after heavy rainfall when the ground is soft gives best results, but this should be done before seed has set. 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 to achieve satisfactory eradication. In most cases this is unpractical."

For longer-term control, the best time to control the weed is before the plant grows to a mature stage and, importantly, before it goes to seed. Where ragwort was present in an area in the previous year and management practices have remained the same, then it is almost certain that issues will re-emerge this year.

Spraying in the rosette stage is recommended as being the most effective chemical control option and the Department of Agriculture’s factsheet points to spring and autumn presenting the best window of control.

Ploughing, followed by an arable rotation, or a programme of spraying if direct seeding, works well, while, if pulling by hand or cutting, it is important that plants are collected and destroyed. Grazing with sheep will also help suppress its growth.

Steps should also be taken to improve grassland management so that it will compete aggressively with ragwort plants.