Japanese Knotweed: The ‘Botanical Bully’ That Can Ruin a Home

Of all the invasive non-native species to end up on Britain’s shores, Japanese knotweed surely takes the prize as the most problematic. If you’re unfortunate enough to have it on your property and you don’t properly deal with it, it could cause serious physical and financial trouble.

This “botanical bully” superweed will stop at nothing to achieve the rampant growth it desires, overtaking everything in its way and leaving behind an almost insurmountable trail of destruction. It’s the stuff that home nightmares are made of — and there’s practically nothing you can do on your own to stop it.

If you do happen to see Japanese knotweed springing up in your garden or elsewhere around the property — identifiable by bamboo-like shoots and heart-shaped leaves — naturally, you’ll want to get rid of it yourself. But simply spraying this incredibly hardy species with weedkiller won’t kill it off and it’s unlikely digging it up will work either. If only a small piece of the root system remains in the ground, it will quickly start sending out new shoots and you’ll be stuck with the same problem.

Japanese Knotweed Home-Value Worries

The papers are full of stories about homeowners battling Japanese knotweed and causing all sorts of structural and other problems to their properties. A recent one involved a pensioner in Wales who was trying to sell his home for the estimated sale price of £130,000. But, when a surveyor had a look at the property and discovered Japanese knotweed on it, the price was slashed to just £70,000. A £60,000 loss is a huge hit to any homeowner, especially an elderly person who is no longer working.

The same thing happened to a 91-year-old woman in Wales, which along with many southern parts of England is a hotspot for Japanese knotweed infestations. The woman was described as “desperate” to sell her house so she could move to a nursing home, as she needed the funds to pay for it. But she was told that because Japanese knotweed was encroaching onto her small property from an infestation in neighbouring vacant land, she would get just over half her home’s value. That’s a mere £45,000 instead of the expected £80,000.

It’s not only the value of these houses plummeting and their owners hoping to sell them at whatever price. There’s also the matter of who’s going to buy them. Practically everyone needs a mortgage to buy a property, but getting one for a house with Japanese knotweed growing on the property is also certainly not going to happen. It’s a no-win situation unless something is done to get the weed off the property for good.

Professional Japanese Knotweed Help

If a surveyor’s report indicates there’s Japanese knotweed growing on a property, mortgage providers will now typically insist on professional extermination, with a guarantee, before going ahead with an approval. So, what does a professional Japanese knotweed eradication company do that the average homeowner can’t to stamp out this ferocious pest? Usually, they offer a number of solutions, but mainly herbicide treatment and dig-outs.

These expert Japanese knotweed removal firms don’t just use any old weedkiller either. They have potent herbicides that are not available to buy in shops and use these to treat infestations of Japanese knotweed over a period of time that may be up to a year or more. It can be relatively inexpensive and, as long as you can wait for the treatment to conclude, is usually effective.

But if time is not an option — due to an impending house sale, for instance — a full dig-out of the plant and its entire entrenched root system can be done. The procedure only takes a few days and some Japanese knotweed removal companies have developed specialist machinery to ensure the root structure is fully taken out and that there’s minimal disruption to the site. After the work is done, an insurance-backed guarantee covers any additional work for five or ten years.

That’s knockout punch that says a final sayonara to Japanese knotweed.