Invasive species are species that have been introduced by humans and have a negative impact on the economy, wildlife or habitats of Ireland. One species which has created significant problems in Ireland is Japanese Knotweed. Japanese knotweed (Fallopia japonica), was introduced as an ornamental plant in the 19th Century from Japan, it has spread across Ireland, particularly along watercourses, transport routes and waste grounds.

Ecological management

Japanese Knotweed is often confused with other similar looking plants. If you suspect Japanese Knotweed is growing on your property/site, Eire Ecology will carry out a site visit to correctly identify the plant, devise a management plan and carry out works to eradicate the plant before it causes damage.

Japanese Knotweed is a pretty ornamental plant so why is it a problem?

Japanese knotweed can:

  • Seriously damage houses, buildings, hard surfaces and infrastructure growing through concrete, tarmac and other hard surfaces, usually where weaknesses already exist.
  • Threaten native plants and animals by forming dense thickets and releasing a chemical subsatnce to inhibit other plants growth.
  • Block routes used by wildlife to disperse.
  • Riverside Japanese knotweed damages flood defence structures and reduces the capacity of channels to carry flood water.

How does it spread?

Japanese Knotweed has a unique ability to grow a new plant from tiny amounts of cut stem, crown or rhizome. Therefore it is important not to disturb a Japanese Knotweed plant in any way as it will spread rapidly.

Reference Website :

Water Fern

Giant Hogweed