Japanese knotweed is a strong-growing, clump-forming perennial, with tall, dense annual stems. Stem growth is renewed each year from the stout, deeply-penetrating rhizomes (creeping underground stems).
New legislation -
An amendment to the Anti-social Behaviour, Crime and Policing Act 2014 includes Japanese knotweed and other invasive non-native plants. Full details of how this will work for the homeowner are not yet available, but here are some key points:
It is not illegal to have Japanese knotweed in your garden.
On your property, you should aim to control this plant and other invasive non-native plants such as Himalayan balsam and giant hogweed, to prevent them becoming a problem in your neighbourhood. If they have a "detrimental effect of a persistant or continuing nature on the quality of life of those in the locality", the legislation could be used to enforce its control.
Identification is important. Japanese knotweed can be confused with other plants including Persicaria microcephala (e.g. P. microcephala 'Red Dragon'),Leycesteria formosa and Houttuynia cordata
Where problems with Japanese knotweed occur in neighbouring gardens, we suggest that you speak or correspond directly with your neighbours (who may already be taking action to control this difficult weed). These informal steps should be taken before contacting your council to talk about control using the legislation.
In spring and summer, bamboo-like shoots grow to 2.1m (7ft) tall. Leaves are up to 14cm (5½in) in length and the creamy-white flower tassels produced in late summer and early autumn reach up to 15cm (6in).
The stems die back in winter leaving distinctive stands of dead canes.
Japanese knotweed was introduced from Japan in 1825 as an ornamental plant. The plant is not unattractive but its rapid annual growth and relentless spread, allows it to easily overwhelm other garden plants. Where established as a wayside weed, native plants are also aggressively over-run.
Although it does not produce seeds, it can sprout from very small sections of rhizomes and, under the provisions made within the Wildlife and Countryside Act 1981, it is an offence to cause Japanese knotweed to grow in the wild. Much of its spread is probably via topsoil movement or construction traffic.
How to Control it
Call Tree Degrees and we will survey to determine how much of a problem it is within your grounds and provide you with a quotation for its treatment and, if necessary, removal. See our Contact Us page for details of your preferred way to get in touch with us.