How To Identify Japanese Knotweed

Japanese Knotweed is now recognised as the fastest growing plant in the UK, but identifying it can often be challenging as the characteristics of the plant can vary depending on the season. With that in mind, WWCS have come up with some key features to look out for.

The first thing to remember is that Japanese Knotweed is a hardy plant, often remaining dormant underground over the cold winter months, - this can sometimes deceive people who think they have succeeded in removing it, but don't be fooled! This plant can grow from what is known as a rhizome, a horizontal stem that continuously grows underground and forms the basis for all vertical stems to grow out of.

It is highly unlikely that your garden will be free from Japanese Knotweed permanently unless these rhizomes are dealt with correctly and removed. This can be done by repeatedly destroying any regrowth or the use of chemicals over several seasons.

With red and purple shoots appearing from the ground in early spring, these stems grow rapidly and begin to form hollow canes that are strong enough to support the plant, which can stand up to 3 metres tall. These canes are speckled with purple and give Japanese Knotweed a distinctive colouring in early summer. They rise up directly from the rhizome and this is how the plant can spread across a garden so quickly.

The flowers are one of the easiest ways to identify the plant

Considered by some to be quite beautiful in its own unique way, Japanese Knotweed blooms in late summer with a set of short spiky stems that display creamy white flowers. These flowers are one of the easiest ways to identify the plant, and they are recognised by insects as being a great source of nectar.

Luckily, the seeds of the flower are quite unfertile and the plant usually only spreads through vegetative means. Another identifiable feature of Japanese Knotweed is its leaves, which are vibrant green in colour and usually flat heart-shaped in appearance.

The leaves and flowers will fall as the summer progresses, leaving behind the canes that turn brown and die. In most cases, the canes will remain standing throughout the winter months and can often be seen amongst the new stands in the following spring.

This plant can be difficult to control so for expert assistance, contact WWCS today for help in removing, treating and preventing Japanese Knotweed in your garden.