Japanese knotweed is a non-native invasive plant that can cause serious damage to property and infrastructure in the UK. It is a fast-growing plant that can reach up to 2.5 metres tall, and it has distinctive zigzag-patterned stems and heart-shaped leaves. Japanese knotweed is most easily identified in the spring and summer when it is in bloom, but it can also be identified in the winter.

Physical Characteristics to Look For

Japanese knotweed is characterized by its distinctive physical characteristics. These characteristics remain evident even in the winter months, making it possible to identify the plant even when it is not in bloom. Here are some key features to look for:

  • Brown, brittle canes: During the winter, the green stems of Japanese knotweed die back and turn brown, becoming brittle and dry. These canes remain standing throughout the winter, providing a visible indication of the plant’s presence.
  • Crown structure: Japanese knotweed has a thick, fleshy crown that is located underground. While the crown is not always visible, it can sometimes be seen at the base of the brown canes. This crown serves as the plant’s storage unit for nutrients, allowing it to survive and regrow in the following spring.
  • Zigzag pattern: The stems of Japanese knotweed exhibit a distinctive zigzag pattern, which is evident even when the plant is dormant in the winter. This pattern is caused by the way the nodes of the stem are spaced along the length of the cane.
  • Scorched areas and bare patches: Japanese knotweed releases toxic chemicals into the soil, which can harm surrounding vegetation. This can lead to the appearance of scorched areas of grass and bare patches of earth, providing a clue to the presence of Japanese knotweed.
  • New growth with distinctive stem pattern: Japanese knotweed spreads through its extensive underground rhizome system. During the winter, you may notice smaller plants with the same distinctive zigzag-patterned stems emerging from the ground. These are likely to be new growth from the rhizomes.

Identifying Japanese Knotweed in the Winter

Japanese knotweed rhizome

By carefully observing the physical characteristics mentioned above, you can identify Japanese knotweed even during the winter months. Here’s a step-by-step guide to identifying the plant:

  1. Inspect for brown, brittle canes: Look for the presence of tall, brown, brittle canes with a zigzag pattern. These canes are the most obvious signs of Japanese knotweed in the winter.
  2. Check for crowns: If you see brown, brittle canes, examine the ground around them. You may be able to spot the thick, fleshy crowns of Japanese knotweed.
  3. Observe for scorched areas and bare patches: If you notice scorched areas of grass or bare patches of earth, it could be a sign of Japanese knotweed. However, be mindful that these symptoms could also be caused by other factors.
  4. Look for new growth with zigzag stems: If you see smaller plants with distinctive zigzag-patterned stems, this could be a sign of Japanese knotweed. These smaller plants are likely to be new growth from rhizomes.

Seeking Professional Assistance

If you suspect the presence of Japanese knotweed on your property, it is crucial to contact a professional for a survey. Japanese knotweed is a tenacious plant that can be difficult to control, and it is important to take early action to prevent it from spreading. A professional surveyor will be able to accurately identify the plant, assess the extent of the infestation, and recommend the most effective treatment options.

About Japanese Knotweed Elimination Ltd

Japanese Knotweed Elimination Ltd is a leading provider of Japanese knotweed removal services in Wales. With years of experience and a team of highly qualified experts, they offer a range of effective and reliable solutions to eliminate Japanese knotweed from your property.

For more information on Japanese Knotweed Elimination Ltd and our services, please visit our website at www.knotweed-wales.com.


Japanese knotweed can be a significant problem for landowners and property owners in the UK. By understanding the plant’s physical characteristics and recognizing its signs even in the winter, you can take the first steps towards identifying and addressing Japanese knotweed infestations on your property. Remember, early detection and professional intervention are key to effectively controlling this invasive plant and safeguarding your land.

Contact Japanese Knotweed Elimination Ltd today for a free consultation.