Experts have debunked common myths surrounding Japanese knotweed, Britain’s most troublesome invasive plant.
With 688 verified sightings in Dorset, including in Dorchester, Bridport and Weymouth, the plant is a substantial problem.
According to a YouGov survey, 77 per cent of UK adults are aware of knotweed, but misinformation still causes unnecessary concern for homeowners and buyers.
Environet, a firm of invasive plant specialists, has clarified ten widespread misconceptions.
It is a myth that household chemicals like bleach, petrol or diesel can kill knotweed.
These treatments will rarely be strong enough to destroy the plant’s underground root system.
Another common misconception is that covering knotweed to block sunlight will kill it.
The rhizome will usually grow laterally in search of sunlight.
While knotweed cannot push directly through concrete, it can exploit cracks or weaknesses in the material.
Many believe it is illegal to have knotweed on their property, but this is not the case.
However, allowing it to spread to a neighbour’s property could lead to legal action.
Most mortgage lenders are now willing to provide mortgages on affected properties, as long as a professional management plan is in place, accompanied by an insurance-backed guarantee.
Even if the knotweed has been treated, it must still be declared on the Law Society’s TA6 form when selling a property.
Herbicide treatment can typically be carried out between May and September, but knotweed can be excavated from the ground at any time of the year.
A neighbour cannot be legally forced to remove knotweed from their property unless it spreads across the boundary.
Knotweed should not be put on the compost heap, as it can regrow from a small piece of rhizome.
Finally, knotweed does not spread by seed in the UK, as all the plants are female and no viable seeds are produced.
Environet director Emily Grant said: “There are plenty of unhelpful myths about Japanese knotweed that only add to homeowners’ anxiety.
“It is the most problematic plant in the country, but it can be managed and, with the right treatment plan in place, eradicated for good.
“As we head through autumn, knotweed will start to die back and become harder to spot, but this can be the ideal time to tackle it.”
AloJapan.com