Non-Native Weeds in the UK
Around 2,000 non-native plants grow wild in Britain. Fewer than 200 cause harm — but those few are responsible for structural damage, failed property sales, blocked watercourses and hospital admissions every year. This page covers which species matter, the duties that come with them, and how each one is legally controlled.
Native or non-native? Species such as bracken, ragwort and creeping thistle are native but still legally significant — ragwort is covered by the Weeds Act 1959. See our native problem weeds guide for those.
The species that matter
Japanese Knotweed
Reynoutria japonica
Britain's most damaging non-native plant. Rhizome spreads up to 7m laterally and can affect mortgage lending decisions.
Japanese Knotweed treatment →Giant Hogweed
Heracleum mantegazzianum
Sap causes severe phytophotodermatitis — chemical burns that recur in sunlight for years. Never strim it.
Giant Hogweed treatment →Himalayan Balsam
Impatiens glandulifera
Explosive seed pods fling 800+ seeds up to 7m; riverbank stands collapse in winter and drive bank erosion.
Himalayan Balsam treatment →Bamboo (running species)
Phyllostachys spp.
Not on Schedule 9, but running rhizome causes knotweed-scale boundary disputes and structural damage claims.
Bamboo (running species) treatment →Rhododendron ponticum
Rhododendron ponticum
Shades out native ground flora and hosts Phytophthora ramorum. Dominant across upland Wales and Scotland.
Rhododendron ponticum treatment →Floating Pennywort
Hydrocotyle ranunculoides
Grows up to 20cm a day, blocks watercourses and deoxygenates water. Requires EA-notified aquatic methods.
Floating Pennywort treatment →Cotoneaster
Cotoneaster spp.
Bird-spread berries colonise limestone grassland and walls; several species are listed.
Cotoneaster treatment →Parrot's Feather
Myriophyllum aquaticum
Aquatic invader that chokes ponds and drainage ditches; fragments regrow from a single node.
Parrot's Feather treatment →Japanese knotweed does not stop on its own
Identification, treatment and guaranteed eradication plans.
What the law asks of you
Wildlife and Countryside Act 1981, Section 14
It is an offence to plant or otherwise cause any Schedule 9 species to grow in the wild. Allowing contaminated soil, arisings or machinery to move species off site can constitute this offence.
Environmental Protection Act 1990
Cut material and excavated soil containing non-native invasive plants is controlled waste. It must be handled, carried and tipped under duty of care with the correct EWC coding and a licensed carrier.
Anti-social Behaviour, Crime and Policing Act 2014
Councils and police can issue a Community Protection Notice where knotweed or similar growth from your land has a persistent, unreasonable effect on the quality of life of others.
How we control them
Survey & identification
Species confirmation, extent mapping and a written report you can give to a lender, solicitor or planning officer. Phone and photo identification is free; a full professional site survey starts from £250.
Treatment programme
Targeted foliar, stem-injection or aquatic-approved application at the right growth stage, repeated across seasons, with a £10M-insured guarantee on qualifying programmes.
Excavation & disposal
Where a timescale demands it: dig-and-dump, on-site burial under permit, root barrier installation and licensed carriage with full waste documentation.
Non-native weeds: common questions
Related services & coverage areas
Continue reading about the work we do and the areas our teams cover.