Spotted Japanese Knotweed? Here’s What You Need to Do

If you’ve been unlucky enough to find Japanese knotweed in your business’s premises or your own home, don’t panic. While the plant species has gained a notorious reputation thanks to the damage it can cause, professional support is available to help you put a stop to any further growth. Here’s how to deal with an invasive plant outbreak safely, without making the issue any worse, or spreading plant fragments any further. 

What is Japanese Knotweed? 

Now found growing all over the world, Japanese knotweed is an invasive plant species that spreads incredibly quickly. Roots can shoot as far as 7m underground, making it difficult to eradicate fully at once – so if you’re new to Japanese knotweed, be aware it’s a problem that will take time to remove. Because it grows so extensively, it’s now illegal to grow or dispose of knotweed in the UK without going through the correct procedures. Left to its own devices, knotweed can stop other plants from growing, and even cause serious issues for building foundations: roots can grow through wood, tarmac and even concrete. 

How to deal with a Japanese Knotweed infestation

Keep the area as isolated as possible 

Once you’ve spotted any signs of knotweed on your property or premises, it’s important to act straight away. Thanks to its invasive nature, Japanese knotweed can spread incredibly quickly, so to avoid further damage, it’s best to sort the issue as soon as possible. If you can, avoid planting anything else in the area and direct foot traffic away. Disrupting the soil could cause roots and rhizomes to spread further, causing greater issues down the line. 

Enlist the help of professional advice 

Every Japanese knotweed infestation is different, depending on the area and climate it’s growing in. Because of this, the very best option you have when it comes to a Japanese knotweed outbreak is getting professional advice. Especially if it’s growing near your home, office building or commercial premises, removing knotweed safely and permanently is crucial to avoid continuous regrowth and prevent expensive damage. 

If you’re unsure where to look for professional support. Eradicating Japanese knotweed on a bespoke basis means you can ensure the weeds are gone for good, rather than investing your own time and money without seeing permanent results.  

Make sure the plant is in healthy condition

While you might be tempted to try and weed out the problem plant yourself, experts recommend you take a step back. Cutting down the stalks above ground will actually have the opposite effect of stimulating rhizome growth, spreading fragments across the ground, and encouraging the plant to grow further. 

Removal should begin during the best possible time of year, too. While Japanese knotweed usually takes about three years to eradicate fully, the plant dies back in winter, only emerging in early summertime. For permanent eradication to take place, the plant needs to be as healthy as possible, with roots, stems and rhizomes clearly visible. 

Check out local disposal centres

By UK law, you need to dispose of Japanese knotweed correctly, to prevent the invasive species from spreading and leading to further infestations. It is illegal to either cause or allow the plant to grow in the wild. Rather than disposing of the weed in your compost bin or local tip, you need to do your research to find a centre that deals with controlled plant waste and that will eradicate the plant for good.

Gardening course for beginners from GardenAdvice

One day gardening courses especially created for beginners run in your own garden by the GardenAdvice expert gardeners. Available as a gift voucher for the gardener in your life. Become a gardener with the GardenAdvice Gardening Course. If you are new to gardening it can all seem a bit complicated at first with all the Latin names and the gardening terminology. GardenAdvice.co.uk have developed a especially designed short one day course to be able to teach you all the basic skills of gardening to get you started. The courses in your own garden cover such basic skills as pruning, correct digging methods, growing your own shrubs and creating the perfect lawn. See some of our clients our gardening course and our MyGardenTeam service on Instagram and the client section on the GardenAdvice website. For further information visit or gardening courses section.