DEFRA has policy responsibility for the five injurious weeds covered by the Weeds Act 1959 (Common Ragwort, Creeping or Field Thistle and Spear Thistle and Curled and Broad Leaved Dock) and also for invasive species, such as Japanese knotweed and water primrose.
We have not issued any specific guidance to local authorities on controlling the weeds covered by the Weeds Act 1959. However, the Code of Practice on How to Prevent the Spread of Ragwort provides comprehensive guidance on how to develop a strategic and cost-effective approach to control of common ragwort. It is intended for use by all landowners and occupiers but is particularly relevant for large-scale organisations managing significant land areas, including local authorities and other public bodies. The code of practice and other information about the control of injurious weeds is available on the DEFRA website.
Advice on the management of invasive non-native weeds is available from a number of sources including the websites of the Environment Agency and the Great Britain Non-Native Species Secretariat. In addition, DEFRA published the Horticultural Code of Practice in 2005, which provides best practice advice concerning the acquisition, use and disposal of plants.