What is Japanese Knotweed?
Japanese knotweed is an invasive non-native species that was first brought into the country in 1825 by the botanist Phillipp Franz Von Siebold to be cultivated for ornamental gardens. This was because of its attractive reddish-brown bamboo like stems, shovel shaped leaves and hanging white flowers.
It was only in 1981 Japanese Knotweed was identified as an invasive threat after it was used extensively in gardens and for stabilising railway embankments.
Is Japanese Knotweed poisonous?
No, the plant is not poisonous to humans or pets.
How is Japanese knotweed spread?
Thankfully due to only Female plants being brought to the UK Japanese Knotweed cannot be spread by seed, it is normally spread, unfortunately, by us humans.
This is normally by small fragments of Rhizome getting caught in footwear or transported knowingly or unknowingly by its owners.
Great care should be taken if you have Japanese knotweed growing in your garden or see it growing out and about to not disturb it.
Is Japanese Knotweed illegal to own?
No, the plants are not illegal to own but it is illegal to allow Japanese Knotweed to spread into the wild. Which, in simple terms, means allowing it to grow under your fence into your neighbour’s garden or off your property. If this was to happen, you can be liable for any costs for control or damage caused to neighbour’s property.
Will Japanese Knotweed make my house fall down?
Japanese Knotweed will not make you house fall down but it will take advantage to any existing damage such a cracks or poorly constructed buildings. This means Japanese Knotweed can push over walls, push though tarmac etc.
How do I get rid of Japanese Knotweed?
Best practice is to treat Japanese knotweed where it stands with a herbicide treatment, and this should be carried out by qualified professionals who can offer guarantees of control. Unfortunately, Japanese knotweed control is not a quick process as herbicide treatment plans can take up to five years, or possibly longer in some cases.
Herbicide treatments are normally carried out in late summer to early autumn before the stems die back for winter and the plant goes dormant.
No attempt should be made to dig up Japanese Knotweed as it will only lead to spreading the plant around and you can be fined if you are caught disposing of Japanese knotweed illegally.