P. ramorum can cause extensive mortality in larch trees, particularly in the wetter West of Scotland. It was first found in Scottish plant nurseries in 2002 and in gardens and parks in 2007. Infection on Scottish larch trees was confirmed in 2010. A revised Scottish Forestry P. ramorum on larch Action Plan was published in June 2021. Summaries of actions to be taken in the three zones – Priority Action zone (PAZ), Risk Reduction Zone (RRZ) and Management Zone (MZ) – can be found on the Scottish Forestry website. Statutory Plant Health Notices (SPHNs) are issued requiring the felling of larch trees infected with P. ramorum plus larch within a 250-metre buffer zone everywhere in Scotland outside the Management Zone. More localised removal of Rhododendron ponticum, which can also host the pathogen, is also required.

This is important information not just for foresters, but for other tree ‘owners’ such as land managers. Please circulate this information to any practitioners or groups that you feel should be updated with the changes to the Action Plan. The Scottish Forestry website also has biosecurity information and disease biosecurity posters for land managers to ensure forestry workers and members of the public take appropriate biosecurity actions to minimise the risk of spreading P. ramorum.