Overview

• Specialists say dieback makes knotweed harder to spot in autumn yet call this a good moment to identify patches and plan removal, with excavation possible year‑round and herbicide programmes typically May to September.
• Experts warn bleach, petrol, diesel or simple covering will not destroy the rhizome and advise against composting any fragments that can readily regrow.
• Guidance clarifies that UK knotweed does not spread by seed and cannot push through intact concrete, though it will exploit cracks and disturbed soil.
• It is not illegal to have knotweed, but allowing encroachment over a boundary can trigger private nuisance claims, and any past infestation must be disclosed on the Law Society TA6 form when selling.
• Industry advice states most lenders will consider mortgages on affected properties if a professional treatment plan is in place with an insurance‑backed guarantee.