What is Japanese Knotwood
Japanese knotwood, also known as Fallopia japonica, is a tall, fast-growing Japanese plant of the dock family. It features long bamboo-like stems, small lacy clusters of white flowers & pointed leaf tips. It was brought to the UK as an ornamental flower; however, it has quickly become a big problem for homeowners.
In the words of the Environmental Agency, Japanese knotweed is:
But why is it such a threat? We look at some of the reasons below.
- Japanese knotwood can grow 3-4 meters in as little as 10 weeks which is the equivalent of 2 grown adults!
- Its roots or rhizomes can spread 7 meters horizontally and potentially compromise the buildings’ structure.
- If evidence of Japanese knotwood is found by a bank’s valuer or it has been a known problem in surrounding areas, a specialist survey will have to take place. This can put off lenders to the point where they won’t lend.
- It can grow up to 20cm in the proper temperatures and surroundings daily!
- It can even grow through concrete and tarmac, and its roots can go down up to 3 meters deep.
- There are currently no natural predators in the UK to combat it, meaning it can grow without interruption swamping other plants and preventing them from growing.
- Although it does not produce seeds, Japanese knotweed can grow from tiny fragments of rhizomes allowing it to spread very quickly & easily.
- Knotweed costs the UK economy £166 million annually for treatment and in-home devaluations.
What does Japanese Knotweed look like?
Below is a picture showing what Japanese knotwood looks like during the different seasons.
What can I do about it?
1. Dig it all out
You can dig out Japanese knotwood, but if even a tiny piece of its root is left behind, it can grow again into a new plant.
Also note that Japanese knotweed is classified as controlled waste, so if you dig it up, you can only dispose of it at licensed landfill sites.
2. Kill it with chemicals
You can use chemicals to get rid of it. For example, treatments containing glyphosate will work, but it can take up to five years of treatment to get rid of the weed completely.
3. Eat it
Yes, you can eat it, but you’d need to eat a lot to get rid of it completely!
Need more advice? Get in touch with the Housebuyers4u team if you have any specific questions. Our national home buyers reviews can speak for themselves in demonstrating our team’s property expertise whether you are buying or selling.