Japanese Knotweed vs Your Home

knotweed vs Your Home japanese knotweed leaf

The dreaded Japanese Knotweed, an invasive plant that now thrives in Britain, can cause huge damage to your property and is very difficult to get rid of. Identified by its long, bamboo-like shoots with flecks of purple, it grows up to seven-foot high and produces branches with shovel-shaped leaves. The plant is very quick growing and has flowers that can be as large as 6 inches in diameter.

Although it dies back in winter, it reappears in spring, and because it grows so fast, can easily overwhelm and suffocate other flowers and plants in your garden. Although it doesn’t produce seeds it sprouts up prodigiously from small sections of its own shoots. Like an ice berg, most of the plant is found under the ground and it’s almost impossible to dig out and not leave any shoots behind without the help of a professional company.

I’m considering buying a property that may have Japanese Knotweed. What are the implications?

If the property you’re looking to buy shows any signs of Japanese Knotweed, you need to speak to the vendor to establish exactly how serious the problem is. Sellers are obliged, by law, to disclose the existence of Japanese Knotweed during the enquiry stage of a property transaction.

Because the shoots of the plant are almost invisible in the cold winter months, you’ll probably not be able to detect it on your inspection of the property. The problem is further compounded by the fact that if the plant has encroached onto a neighbour’s property and it’s not rectified, you may very well have to face a ‘nuisance’ claim.

Although it’s an invasive plant, and a proverbial pain in the posterior, it’s not illegal for someone to have it growing in their garden. However, the law does not permit it to be out of control and, if it is, the owner of the property will almost certainly be forced to take remedial action. Speak to a commercial Chartered Surveyor, or solicitor, if you need any more information or professional advice.

Will I be able to obtain a mortgage on the property?

The presence of Japanese Knotweed could cause you problems if you’re applying for a mortgage. Some lenders refuse to grant a mortgage outright, while others will consider your application only if the plant is completely eradicated by a professional company that provides an insurance-backed guarantee.

Will Japanese Knotweed cause any structural damage to the property?

If grown close to the walls or foundations of a house, Japanese Knotweed can easily cause damage to the structural integrity of the property. The plant grows deep underground and is strong enough to penetrate through bricks and mortar and concrete. Rectification works to repair or return the property to a structurally sound state can be very expensive and time consuming. Structural damage could also become a major problem if you decide to sell the property in the future.

Speak to your building surveyor to get an accurate picture of how the property is affected and what it would take to rectify the problem.

What do I need to do if I’m selling a property with Japanese Knotweed?

Never try to hide the existence of Japanese Knotweed in your garden. Let your potential buyer know it’s there, because concealment of this plant is a very serious matter that could lead to the buyer lodging a claim against you. If you’re considering removing or controlling the plant, there are a number of ways in which you can do this:

  • Weed killers

There’s a small selection of weed killers on the market that can kill Knotweed, but most require multiple applications. Those with the ingredient Glyphosate have proved to be the most effective.

  • Self-removal

You can try digging out the plant yourself, but because the shoots penetrate so deeply underground, it’s very difficult to ensure that you remove all the roots and shoots and that no re-growth occurs. Also, you’re not allowed to dispose of the remains of the plant at landfill sites. It’s best to allow the cut canes to dry out on your property and then burn them.

  • Professional removal
    There are a number of highly skilled professional companies that can remove Japanese Knotweed for you. What’s more, some of them will provide insurance guarantees, which is particularly helpful if you’re selling a property, or applying for a mortgage to buy a property. Of course, this will come at a cost, but you’ll then have peace of mind knowing that the problem has gone for good.

Although weed killers, or self-removal, may be appear to be a cheaper option, if not carried out properly you could have bigger problems later on down the line. Where there is some evidence of Knotweed, it’s a good idea to have a Chartered Surveyor assess the property and make sure there aren’t any potential structural issues.

This article was written by Dakota Murphey.


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