Invasive plants as controlled waste
Japanese knotweed and other Schedule 9 species are classified as controlled waste when removed from the land on which they are growing. This applies regardless of whether removal is carried out by a professional contractor or the landowner.
Waste carrier licensing
Transporting controlled waste requires registration as a waste carrier with the appropriate environmental regulator: the Environment Agency in England and Wales, SEPA in Scotland, NIEA in Northern Ireland.