Invasive non-native species
Invasive Non-native Species (INNS) are plants, animals, fungi and micro-organisms which have been introduced to parts of the world where they would not naturally be found.
They have the ability to spread causing damage to the environment.
- Giant hogweed
- Himalayan balsam
- Japanese knotweed
Giant hogweed is an immensely tall umbellifer (member of the carrot family) that displays large, white, umbrella-like clusters of flowers. Its hollow stem is ridged and purple-spotted, and its leaves are large and divided.
Himalayan balsam has large, pink flowers shaped like a bonnet; these are followed by hanging, green seed pods.
Japanese knotweed can grow to over three metres tall and forms dense thickets. Some of the distinctive features of the plant are:
- zig zag stems
- lush, green, shield-shaped leaves
- purple speckled stems
- white flowers in summer
Waste material from these plants is classed as ‘controlled waste’ under the Environmental Protection Act 1990. It must be disposed of at a suitably licensed or permitted waste site.
It is an offence to plant or cause this species to grow in the wild. This can include spreading it by strimming, flailing or dumping contaminated material.
Report Japanese knotweed on private land
Japanese knotweed is the landowner’s responsibility. If you don’t know who the landowner is, you can contact the Land Registry.
If it is on your land, you must not let it spread either into the wild or onto someone else’s property. You can either treat it yourself, or by hiring a specialist company. It can take a number of years to get rid of Japanese knotweed.
Invasive Non-Native Species (INNS) Map
Explore the distribution and impact of INNS in Wales using the Natural Resources Wales INNS Map.