Japanese knotweed (Fallopia japonica) is a non-native invasive species. It is a perennial plant that was introduced into the UK as an ornamental plant from Eastern Asia in the 19th century.
Japanese knotweed is an invasive weed, producing tall bamboo like canes, up to 3m. The canes are purple coloured, and produce branches from nodes along its length. The Japanese Knotweed has clusters of white flowers in autumn.
It is most notably seen as a smaller plant, where it is sprouting through cracks roadsides, riverbanks and derelict buildings. Across the UK and Ireland Japanese Knotweed creates problems due to the impact on biodiversity, flooding management and damage to property. It is an offense to plant or cultivate Japanese Knotweed. It is also classed as controlled waste and requires disposal at licensed landfill sites.
Identifying Japanese Knotweed:
- To identify Japanese Knotweed in the summer look for tall bamboo like shoots up to 3 meters in height
- Small red shoots in April as the knotweed emerges
- Red / purple coloured stems
- Distinctive raised nodes
- Leaves arranged in a zigzag pattern along the stem
- White flowers in clusters in the autumn
- Hollow stems
- Orange centred rhizome (root)
Treating Japanese Knotweed
Road Safety Contracts use a variety of methods to remove Japanese Knotweed including Knapsack spraying, stem injections and dig and dispose of environmentally. All Japanese knotweed removal operations are carried out by experienced, skilled operators who hold a certificate of competence recognized by the DARD (NI).