Knotweed Ireland


On completion of our training programme your staff gain the ability to identify, map and manage the Knotweed species.

Subjects in the training programme:

* Ecological information on Japanese knotweed

* The prevention of Japanese knotweed spreading

* Managing the Japanese knotweed problem

* How to use root barrier membranes

* Treatment or disposal of Knotweed on site

* Disposal of Knotweed off-site

* How to move soil containing Knotweed

* Long term effects for land use

* Legislation


The European Communities Birds and Natural Habitats Regulations 2011 (SI 477) were signed into Irish law on 21 September 2011. The intention of these Regulations is to considerably increase the controls of the introduction of non-native species to the Republic of Ireland.


Regulation 49 States: Prohibition on introduction and dispersal of certain species


This places restrictions on the introduction of any plant species listed in Part 1 of the Third Schedule.

A person shall be guilty of an offence if they: plant, disperse, allow or cause to disperse, spread or cause to grow the plant in the Republic of Ireland.


Plant Description

Knotweed is a giant perennial which grows at an alarming rate of up to 10cm per day in any type of soil.

It forms dense clumps of up to 3m (10ft) in height. Japanese Knotweed thrives on disturbance and spreads by natural means and by human activity. Very small fragments of rhizome (underground stems), as little as 0.7g - approximately the size of a fingernail - can produce fresh new plants.

Below ground is where this invader causes the biggest problems, as each stand creates a rhizome network that can extend to 3m in depth and 7m in all directions.


Contact Details

Phone: 086 3080356   or 087 7643923

Click a name below to send an email to that person.

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Martijn Leenheer 087 7643923  
Leo Cosgrove 086 3080356