Non-native plants have been introduced to areas outside their natural range by human activity and can become invasive if they spread and cause environmental, economic or social problems.

Plants such as Himalayan balsam were introduced in the Victorian era as ornamental garden plants but have ‘jumped the garden fence’ and spread into the countryside, where they can out-compete our native wildflowers.

Japanese knotweed is a notorious invasive non-native plant as its underground rhizomes can cause structural damage to buildings. Giant hogweed, which originates from the Caucasus Mountains, was brought to the UK in the nineteenth century. It has invaded riverbanks and is a health hazard as its toxic sap causes burning blisters on human skin, particularly in bright sunlight.

American skunk cabbage has colonised species-rich wet woodlands where it spreads quickly and becomes dominant as its huge leaves block out the light. American skunk cabbage, along with some other invasive non-native garden plants, cause such serious problems to our environment that they are now banned from sale.

Catherine Chatters, the Trust’s New Forest Non-Native Plants Officer, provides practical help and advice on how to control a wide range of invasive non-native plants.

For gardeners who find themselves with a surplus of garden plants, it’s very important to dispose of them responsibly. Aquatic plants such as parrot’s feather, New Zealand pygmyweed and water primrose cause serious problems if they are dumped or planted in the wild. They spread rapidly and dominate ponds and wetland habitats, harming our precious native flora.

Everyone can ‘Be Plant Wise’ by following three simple steps: