To help protect and enhance the flora and fauna of Cardiff Bay, the Cardiff Harbour Authority undertakes a programme to control the growth and spread of nuisance plants on land around the Bay. Nuisance plants are non-native plants which have been introduced to Britain mainly for ornamental purposes. If left unchecked these plants will rapidly colonise large areas of land replacing native species and significantly reducing the wildlife value.

There are three nuisance plants present around the Bay, these are Japanese Knotweed, Himalayan Balsam, and Giant Hogweed. As well as exhibiting the properties described above, Giant Hogweed can also pose a risk to human health as direct skin contact with sap from the plant can result in irritation, swelling and blistering.

Regular surveys are carried out to identify areas of land colonised by these plants. All plants located are treated with a herbicide several times during the spring and summer to reduce their growth and eventually eliminate them. This work is undertaken by a specialist weed control contractor organised through the ‘Grounds Maintenance and Weed Control’ Service Level Agreement in place between the Harbour Authority and Cardiff County Council’s Parks Services.