Guides

Invasive non-native plants: what gardeners need to know

A handful of garden escapes cause serious harm to rivers, woodland and property. Here's what the law says, which plants to watch for, and how to get rid of them safely, for gardeners in England and Wales.

The law in brief

Rule	What it means
Growing it in the wild	It's an offence to plant, or otherwise cause to grow in the wild, any plant listed in Schedule 9 of the Wildlife and Countryside Act 1981. That includes dumping garden waste or soil containing it.
If it's already in your garden	It isn't an offence to have a listed plant growing on your land, and you don't have to remove it. You must stop it spreading, and you could be responsible for damage it causes beyond your boundary.
Species of special concern	A shorter list of plants can't be kept, grown, sold, swapped or transported at all, including seeds and cuttings, under the Invasive Alien Species Order 2019.
Banned from sale	Some aquatic plants, including water fern and Australian swamp stonecrop, can't be sold in England.

Invasive plants to watch for

Plant	Schedule 9	Species of special concern	Why it matters
Japanese knotweed	Yes	No	A piece of root as small as 1 cm can grow into a new plant. UK plants are almost all female, so it spreads by fragments, not seed.
Giant hogweed	Yes	Yes	Its sap makes skin very sensitive to sunlight, causing burns, blisters and long-lasting scarring. Wash skin that touches it straight away and keep it out of the sun.
Himalayan balsam	Yes	Yes	Explosive seed pods throw seed up to 7 m, and seed floats downstream, so it lines riverbanks.
Rhododendron ponticum	Yes	No	Seeds travel up to 100 m on wind and water, and dense thickets shade out native plants.
Australian swamp stonecrop (New Zealand pigmyweed)	Yes	No, but banned from sale	A single node on 10 mm of stem can root, so it smothers ponds in dense mats.
Floating pennywort	Yes	Yes	Fragments drift downstream and choke waterways; controlling it costs an estimated £250,000 to £300,000 a year in Great Britain.
Parrot's feather	Yes	Yes	Forms dense mats on the water surface.
Water fern	Yes	No, but banned from sale	Mats up to about 30 cm thick block light and oxygen; green at first, turning red late in the season.
Few-flowered and three-cornered garlic	Yes	No	Spread by bulbils and seed on boots, tyres and dumped garden waste, carpeting woodland floors in spring.
Cotoneaster (five species)	Yes	No	C. horizontalis, C. integrifolius, C. simonsii, C. bullatus and C. microphyllus are listed. They're still sold, but mustn't be allowed to grow in the wild.
Spanish bluebell and hybrids	No	No	Not listed in England and Wales, but they cross freely with native bluebells, so avoid planting them near wild bluebell woods.

Japanese knotweed is the one most likely to affect a home sale or mortgage, and it needs a professional programme over several years; our guide to Japanese knotweed treatment explains the options, costs and rules.

Getting rid of invasive plant waste

Most invasive plants can't go in the compost bin or the council's garden waste collection. Soil or plant material containing them may count as controlled waste, so it has to go to a landfill site permitted to take it, with a registered waste carrier. Burning on site needs care and, for businesses, a waste exemption, so check with your council first.

Reporting a sighting

Sightings help agencies catch new outbreaks early. You can record any non-native plant on iRecord, or use the INNS Mapper app, and GOV.UK asks people to report listed plants that aren't yet widespread so they can be eradicated. Profiles of individual species are on the way and will appear here as they're published.

Not sure what you've got?

If you're in County Durham, I can identify a plant for you on a garden consultation before you spend anything on treatment, and help you plan what to do about it.

About garden consultations

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