How to identify Japanese Knotweed

How to identify Japanese Knotweed

Japanese knotweed is easily identifiable through its distinctive leaves and flowers. It’s flower is white and looks a little bit like a buddleja.

Please have a look at our gallery to see examples of Japanese Knotweed.

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 plants become 100% developed by the early summer season and very old stalks are hollow inside with very obvious dark purple spots and form thick shoots that grow up to three metres high. Flowers grow in late summer and these consist of groups of sharp spiky stalks with small creamy-white flowers all over them. These are a great source of nectar for insects such as bees and wasps. Japanses Knotweed seeds are not very fertile and in the UK, it spreads the most by vegetative means.

The helpful BBC video demonstrated how to identify and treat Japanese Knotweed

In late autumn the leaves will fall to the ground and the cane becomes dark brown in colour. Japanese knotweed remains dormant over the winter months.

The stems die back to ground level in winter. Japanese knotweed likes to grow in all conditions and in many terrains. This is the problem. In winter Japanese knotweed can look like it’s dying off underneath it is still very much alive.

Sources

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Japanese Knotweed
FAQs

Read the most common questions about Japanese knotweed here and find out many of the common answers. Us this page as your start in the battle against Japanese Knotweed.

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What is Japanese Knotweed?

Japanese Knotweed (Fallopia japonica) was introduced to Britain togetin the middle of XIX century as an ornamental garden plant. It was first described by Dutch naturalist Maarten Houttuyn in 1777 from Japan under the name Reynoutria japonica.

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How to identify Japanese Knotweed

Japanese knotweed emerges as small shoots green/purple in colour. As the plant develops it produces small shield-shaped leaves growing from the stem's many sticking out nodules or knots. Once it's grown in to maturity, the leaves turn bright green colour and can grow to over 100cm in length.

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Japanese Knotweed treatment services

Japanese knotweed infestations can be eliminated through a variety of methods. Depending on factors such as the time you have, the location of the infestation and the environment it's found in the method can vary. Through correct application, Japanese knotweed growth can be limited and prevented from coming back.

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