Japanese knotweed is the most invasive plant in the UK and while most people have heard of it, it’s a particular concern for homeowners, especially ones planning to buy and sell.
How to spot Japanese knotweed
If you suspect you have knotweed, you need to make fairly sure it is before calling in a professional removal service. There are other plants which look very similar to Japanese knotweed, so if you’re not quite sure, you can often send photos to a removal service for more expert identification.
Why is it such bad news?
It’s very destructive. It can cause a lot of structural damage by growing through cracks in concrete and brick, as well as by growing through asphalt and even into drains. This can mean expensive repairs.
Japanese knotweed is very common. It’s been spreading across the UK since it was introduced in the 1850s and now an estimated 4-5% of UK homes are affected.
It’s very difficult to kill. The usual rules don’t apply with Japanese knotweed – you can’t use weedkillers, cover it up, burn it or cut it up. You need, in fact, intense herbicide treatments for two or three years, or specialist excavation.
Japanese knotweed and the property market
Knotweed can scupper sales. Lenders won’t even think about a mortgage unless there’s a professional removal plan in place (and preferably in progress) and with an insurance guarantee.
The cost of treating knotweed can reduce the asking price of a property by as much as 10-15%, depending on how bad the infestation is and how much it’ll cost to remove.
Knotweed doesn’t have to be a dealbreaker
As long as you’re upfront about the presence of the knotweed, you can still sell your property, as long as you are honest with any potential buyers and make sure that there’s a plan in place to eradicate it.
You must, however, be open about it with your estate agent so that they can pass this information on to any potential buyers
