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Invasive Plant Species (Knotweed) Treatment Programme

Donegal County Council is undertaking a 4 year Invasive Alien Plant Species (Knotweed) Treatment Programme on public roads around the county.


Invasive alien plants species are initially transported through human activities outside of their natural range and then survive, reproduce and spread.  These species have negative impacts on the ecology of their new location and when growing close to road carriageways, these species can impact on sight lines, cause damage to the road infrastructure by growing up through the asphalt at the road edge and other structures.


For more information on Invasive Plants Species please see booklet below:

Invasive Alien Plant Species Information Booklet



Report a sighting on a public road


If you become aware of any type of invasive alien plant species including Knotweed along a public road, please report it by contacting the Council in any of the following ways:


Online Report It at


By email: [email protected]


By phone: 074 91 53900



4 Year Invasive Alien Plant Species Treatment Programme


The Council is currently gathering information on the location and scale of knotweed infestations on public roads around the county.


It is expected that each infestation will need to be treated for a minimum of four years in succession to ensure eradication.  The timing of treatment is critical, as is the pesticide to be used in the treatment and late in the season just before the plant dies back for the winter appears to be the most effective. The primary objective of control is the total eradication by targeting the underground rhizome and not simply the aerial parts.


We aim to have a contractor appointed in time for a treatment programme to commence in September 2016 and the use of specialised equipment will be needed for the majority of the infestations.


Transport Infrastructure Ireland


Transport Infrastructure Ireland (TII) introduced an eradication programme on selected national roads in 2016 and they plan to treat knotweed infestations along entire routes and Donegal will be included in the first routes to be treated.  This programme will run in paralled with Donegal County Councils treatment programme on non-national roads.  Transport Infrastructure Ireland (TII) has issued an Advance Notice to landowners in relation to this programme.



At any other location


If you become aware of any type of invasive alien plant species at any other location you should report the sighting to Invasive Species Ireland.


Although many infestations span both public and private lands, the Council has no authority to treat infestations on private lands.  In circumstances where an infestation is thought to have originated from the roadside and from there spread to private lands the Council intends to consult with the landowner to get their consent to allow the treatment of all of the infestation.


For more information on dealing with an infestation on private land visit


No cutting of plants


Signage will be erected at all infestation sites to stop the further spread of these plants. Knotweed is spread from plant fragments and a lack of awareness of the plant among those carrying out roadside hedge cutting is contributing to the spread and as a further management measure it is intended to erect signage at all infestation sites to help prevent them being cut.


IAPS Signage 379 x 269


It will be necessary to continue to cut back hedges where existing infestations are blocking visibility or generally creating a hazard on the road network.  It is planned to do this cutting manually to avoid spreading the infestation and cuttings will continue to be left on site until an alternative disposal method can be agreed.