Japanese knotweed is a herbaceous plant native to Eastern Asia in Japan, China and Korea. OK so what’s all the fuss about with Japanese Knotweed (aka Fallopia japonica)?
The root system and strong growth can damage concrete foundations, buildings, flood defenses, roads, paving, retaining walls and architectural sites. It grows very quickly, 3-4m in as little as 10 weeks and its roots can spread 7m horizontally and compromise the structure of buildings.
Cutting the plant has no real effect as it simply regrows from the substantial roots. Effective treatment involves applying herbicide close to the flowering stage in late summer or autumn. To totally eradicate the plant the roots need to be killed.
The cost of eradication is dependent upon the size of the problem. For a small plant the cost can be a little as £300 per treatment upto as much as £20,000, carried out twice a year for a couple of years. If you were to rip out the weed and just bin it you can face a massive fine or even imprisonment if it isn’t disposed of at a landfill site, or incinerated.
The upshot is this is a big problem in the UK and if not treated correctly it will return with a vengeance.
So what are the other implications of Japanese knotweed in or near my property?
If you wish to buy a house that has Japanese knotweed your very unlikely to get a mortgage as the surveyor will deem the property to be uninhabitable and the unfortunate seller will be sitting on a home drastically reduced in value due to the weed.
If you’re already own the property and want to remortgage, it’s unlikely the lender with allow any further borrowings until proof is available to show the problem is completely eradicated.
With all that said it’s not just your property affected any neighboring properties close to a “Japanese knowtweed home” may suffer the same consequences regards valuation and mortgage restrictions…
Have you had experience of Japanese knotweed?