Japanese knotweed, the menace 4 in 5 don’t recognise

IT has a name which strikes dread into the heart of any property owner.

Japanese knotweed can take years and thousands of pounds to destroy after invading a garden.

But four out of five people have no idea what it even looks like, it has emerged. Many mistake it for similar plants like bindweed.

A You-Gov survey for knotweed removal firm Environet found 19 per cent of people in Britain aware of the invasive plant can actually identify it. People mix it up with plants with heartshaped leaves from the same Invader: Japanese knotweed family, like bindweed, Russian vine and Houttuynia.

It is even confused with common ivy, found in most British gardens and entirely unrelated.

Dr Trevor Dines, a specialist at conservation charity Plantlife, said: ‘Japanese knotweed is an invisible giant. When it first appears, it is hardly there and it can take five to six years to get to the point that people notice it.’

Watch out for its lush green colour and zig-zag, purple-speckled stems. The shield-shaped leaves have a flat base.

The rhizomes, or horizontal stems which produce roots, have white shoots. But cut a Japanese knotweed rhizome open and it will be bright orange inside.

In spring, reddish-purple shoots emerge from groundlevel crimson buds. In the summer, these shoots produce bamboo-like canes with purple flecks and creamy white flowers. In winter, the stems die back to ground level.