The invasive plant spreads easily, whether that’s through disturbed soil or fragments falling from a neighbour’s property.Nicola Roy Spare Time writer and Sam Dimmer East Midlands Head of Brand
06:28, 12 Oct 2025
Japanese knotweed sprouts look very different in winter(Image: Getty)
Gardeners throughout the UK are being encouraged to venture outdoors and search for a potentially damaging plant before winter’s colder temperatures arrive.
Japanese knotweed is an extremely invasive species that spreads rapidly, whether through disrupted earth or pieces dropping from neighbouring properties.
It’s believed to exist in approximately five out of every 100 UK gardens.
Nevertheless, despite its notoriety, it’s frequently confused with ordinary plants sharing similar features.
Mistaking knotweed for a benign plant can result in considerable problems, including costly treatment programmes and possible private nuisance lawsuits from neighbours, reports the Express.
When left uncontrolled, the invasion can cause structural damage, reduce property values and restrict the enjoyment of outdoor spaces.
With such significant consequences, property owners ought to recognise the distinctive features that make knotweed readily identifiable.
Jennifer Holmes from Japanese Knotweed Ltd explained: “It’s crucial all home and land owners know how to spot knotweed because its early detection can reduce costs to remove or control it.
“It’s not OK to simply ignore knotweed – or not be vigilant about looking for it.
“Knotweed will encroach from outside your property boundaries onto your land, it’s quite sneaky in how it does this – usually underground so it’s not visible until it’s too late.
“Right now knotweed still has some flowers and the above ground parts of the plant are quite distinctive, but wait until the winter and all you’ll see is a bunch of brown stems that could be overlooked as pretty much any winter shrub.”
If you’re concerned that a plant in your garden might actually be Japanese knotweed, there are several key features to watch for.
Firstly, examine the leaves – they’ll be spade-shaped with a flat base and pointed tip, displaying a vibrant green colour and growing in an alternating pattern along the stem.
Leaves will be shovel-shaped with a flat base, pointed tip and bright green in colour(Image: Getty)
The stems are hollow with a bamboo-like appearance, reaching heights of up to three metres.
They feature purple speckles and develop in a zigzag formation, becoming brown and fragile during autumn and winter months.
The flowering period should have concluded by now, so you won’t spot any white blossoms among the foliage.
However, the root system is particularly distinctive – there will be a dense network spreading beneath the ground, and when broken, the interior reveals a bright orange colour.
As colder weather arrives, the plant dies back, leaving behind brown hollow canes that frequently remain upright.
Should you discover an infestation, it’s advisable to contact professionals who can assist you in removing it safely.
Comments are closed.