Frequently Asked Questions

Japanese knotweed enters several recognisable phases throughout the year, whilst treatment can take place at any time it’s typically easier to spot during the summer, as this is when the plant is most visible above ground. You’ll first spot small red-purple asparagus-like shoots growing in spring, these can grow up to 10cm a day during the summer and often grow in large patches.

The leaves are the most distinguishable feature throughout the year. These are broad and shield-shaped with a distinctive alternating stem pattern, unfortunately, there are other common plants that look like Japanese Knotweed. Both Lilac and Dogwood share similar shaped leaves. Look for small white creamy flowers and bamboo-like canes to be certain that you have a Japanese knotweed infestation, or hire a professional to survey your property.

Yes! You can eat Japanese Knotweed, it’s similar to rhubarb. 

HOWEVER, we do not recommend doing so. Once you cut the stems, the plant grows even faster than usual. You may think you’re going to save money and have a delicious treat as a bonus but this will eventually bring more stress and costs to your door. 

It is likely that the plant never actually went away. Japanese Knotweed can lay dormant for long periods of time.

Japanese knotweed is a rhizomatous plant, meaning that it has a modified stem system that grows underground (much like a tree’s roots), which can render it dormant for extended periods, making it practically invisible to the naked eye from above the system. Unlike a tree’s roots, however, each rhizome is capable of producing new nodes and sending shoots up to the surface to create a new plant.

japanese knotweed growing through tarmac
Japanese Knotweed can grow through concrete, tarmac, brick and mortar

It is certainly possible to eliminate Japanese Knotweed yourself, however it grows so fast that even leaving a fragment of root the size of a fingernail is enough for the plant to regrow. 

The recommended treatment is to inject the stems. This can be done by professionals who can access stronger herbicides and dispose of the plant correctly.

It is important that you do not dispose of Japanese Knotweed yourself. 

  • Under no circumstances can you dispose of Japanese Knotweed in your compost, recycling, or waste bins, due to its fast spreading and growing nature.
  • It is classed as ‘controlled waste’ under the Environmental Protection Act 1990 and requires disposal by a licensed waste carrier, who will ensure it is disposed of at a licensed landfill site.

It is possible to control the plant yourself, but it is highly recommended that you hire a professional to ensure the plant will not grow back. A professional will survey your garden to determine the extent of the contamination and can create a management plan to ensure the effective removal and reduce the chances of regrowth.

Solutions and treatments which can be provided by a licenced Japanese Knotweed specialist are:

  • A herbicide application program.
  • Sifting and screening.
  • Root barriers.
  • Excavation (if the Knotweed needs removing immediately, usually on commercial sites).
  • Stem injections.

By attempting DIY, you cannot be sure if you are getting the entire root up or causing a bigger problem by spreading it further.

It depends where and how the weed has approached your land. It could be from a neighbour who has allowed the weed to spread. You could have purchased land/property where there has been an infestation that was not declared before your purchase. Legally, it has to be declared that there is/has been a Japanese Knotweed infestation on the property.

You could also claim if the weed has approached your land from public property.  Many successful claimants have received compensation after JKW had approached their land from a nearby railway track.

Still have a question?

We’d be happy to answer  any questions you may have. If you’re not sure if you have Japanese Knotweed and you’d like one of our experts to check it out, you can upload images in our claims form.