Non-native and invasive plants

People have been bringing plants and animals to Scotland for hundreds of years, for various reasons such as farming, horticulture and even accidentally.

Problems occur when these species spread, are hard to control and damage our native wildlife and habitats. These plants and animals are known as invasive non-native species (INNS).

The key to controlling them is to know where they are and reporting sightings is valuable to us. So when you are out for a walk, cycling or fishing, keep an eye out for these two key species.

Himalayan (Indian) balsam (Impatiens glandulifera)

This plant grows to 1-2 metres with bright pink flowers and leaves with rough serrated edges. After flowering it produces large quantities of seed, which explodes from pods and are scattered up to 7 metres away. Seeds can also be transported in water and grow to form dense stands along river banks.

Although bees and other insects feed from the flowers, these stands slow the growth of native species. in autumn the plants die back leaving river banks bare of vegetation and more susceptible to erosion.

For more information and photos see this Wikipedia entry on Himalayan balsam.

Japanese Knotweed (Fallopia japonica)

This is originally from eastern Asia, and with its hollow stems can look quite like bamboo. It has broad oval leaves with a flattened base and cream coloured flowers.

This perennial plant spreads rapidly, sending underground creeping roots as far as 7 metres away from the parent plant. This results in dense clumps of the plant forming, causing damage to soil and even buildings, as well as shading out native vegetation. It can be difficult to get rid of so please let us know if you spot even a small stand of this plant.

For more information and photos see this Wikipedia entry on Japanese Knotweed.

Other invasive non-native species

We also want you to report any sightings of:

How to report

For more information on invasive species and how to report your sightings please email

Countryside and Greenspace Service

Phone: 01355 236644
Email: Countryside and Greenspace Service