‘Knotweed’ in garden may be harmless plant
Homeowners keen to root out invasive menace warned not to mix it up with lookalike bindweed
‘The good news is that bindweed is a nuisance, but not a menace. Unlike Japanese knotweed’
ONE in four people who think they have Japanese knotweed in their garden actually have an innocent plant, experts have revealed.
Japanese knotweed can be disastrous for homeowners as the invasive species can burrow through brickwork, and concrete and cause damage to property. It is extremely difficult to remove and cannot be treated easily with chemicals and requires comprehensive physical eradication, which can cost thousands.
However, as homeowners become increasingly aware of the risk of Japanese knotweed, more false alarms are being reported.
Environet, experts in Japanese knotweed, runs a free identification service for people concerned they may have it, but just one in six are correct.
One in four of the photos submitted by the public are actually bindweed, an annoying but harmless plant, data shows. Dogwood, lilac, Russian vine and Bramble are also weeds most likely to be mistaken for Japanese knotweed.
Bindweed shares similar traits to knotweed, including a rapid pace of growth and vivid green heart-shaped leaves. However, while knotweed can grow without support, bindweed needs to wrap itself around other plants, walls or structures.
An easy way to tell the plants apart is that if it is wrapped around a fence or post to grow upwards, it is likely bindweed and not knotweed.
Bindweed also has l arge, trumpet-shaped flowers while knotweed has small cream-white flowers.
The nuisance weed is a familiar sight in gardens and chokes plants in borders by twining around fences, hedges and other plants.
It can choke plants around it and outcompete larger shrubs and small trees. Its strong underground root system can be difficult to remove entirely if well established.
Knotweed emerges from a winter dormancy in the spring and it often grows in earnest in March and April as the plant can grow four inches a day and reach three metres tall.
Emily Grant, director of Environet, told The Telegraph: “It’s the green heartshaped leaves of bindweed that really worry people, as they are so similar to those of Japanese knotweed.
“The good news is that bindweed is a nuisance, but not a menace. Unlike Japanese knotweed, it isn’t capable of pushing up through patios, paths and sheds, and it won’t cause any damage to your house.” Bindweed, unlike its more hazardous counterpart, can be eradicated with weedkillers, such as Roundup, or i t can be excavated manually.
Ms Grant added: “The problem is that it kills everything and the nature of bindweed means it’s probably wrapped around other much-l oved garden plants.”
Gardeners should dig out the roots by loosening the soil around the base of the plant with a fork and pull out any new growth as it appears. She added: “Like knotweed, bindweed can regrow from small root fragments left in the soil, so disposing of it via green waste or burning it, rather than composting, will help ensure it doesn’t reappear elsewhere.”
The discovery of knotweed was once enough for house sales to fall through or for a potential buyer to be denied a mortgage. But in recent years industry bodies have changed their stance. The Royal Institution of Chartered Surveyors updated its guidance in 2023 to say that its risks are lower than previously thought.
Most mortgage lenders are usually happy to proceed with a sale, even if the plant i s known to be growing on the property, as long as a fully-financed knotweed management plan is in place.
The treatment company used must be a member of one of the trade associations or the Invasive Non-native Specialists Association or the Property Care Association.