Japanese Knotweed Identification

Our team of specialists can help you identify a Japanese Knotweed problem.

Japanese Knotweed is one of the most invasive plant species in the UK and has many guises, depending on the time of the year. Identifying it is not always easy, even if you know what to look for. While an Agronomist will know the differences between Knotweed and commonly misidentified plants, these may not be so obvious to a less experienced person. 

Japanese Knotweed Features

Below are some images and descriptions of the main features of Japanese Knotweed that should help you identify it. However, should you remain unsure – we can help with our FREE Japanese Knotweed identification service.

Heart shaped leaves & white flowers
Bamboo like stems with 'nodes'
New shoots in an established stand
  • The leaves are light green and heart shaped.
  • In late August the plant produces small cream sterile flowers.
  • Around the end of October plants start to die back for the winter.
  • Dead brown canes are the only above ground sign of Knotweed during the winter.
  • New shoots emerge every March.
  • Shoots can resemble asparagus on emergence.
  • Plants can reach 2 metres by the end of May.
  • By the end of June plants can be 3-4m tall, and are identifiable by their bamboo like nature and fleshy green/red tinged colour.
Very new shoots tinged red
Dead canes
Asparagus like appearance

The Rhizome

Twig like appearance
Pale orange/yellow tissue
Brittle and breakable

The rhizome is the underground part of the plant. Rhizomes have a twig-like appearance with a dark brown exterior. The texture of the outer bark is leathery with nodes at 1-2cm spacing, slightly enlarged and ‘knotty’. When the bark is removed, the tissue is pale orange/yellow. They are brittle when fresh and break easily like a carrot. Young rhizomes are white and very soft.

Our FREE Identification Service

Landtech (UK) Limited provide a FREE Japanese Knotweed identification service, where we review photos of your suspected Knotweed plant. If you would like us to identify your plant, click the button below to email us your photos and we will respond as soon as possible.

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