Call for help to combat spread of tree disease

Felling diseased larch1

Forestry Commission Scotland has urged members of the public to join owners and managers of woodland in helping to combat a tree disease hitting larch in the west and north of Scotland.

Phytophthora ramorum (P. ramorum) is a fungus-like disease that affects more than 150 plant species, including Rhododendron ponticum and viburnum, but which is especially destructive on larch trees.

Having badly affected larch in South West Scotland, the disease is also affecting larch in West Argyll, Lochaber and Cowal & Trossachs.

The Commission is asking that anyone visiting or working in larch woodland to first of all ‘arrive clean’ and to also keep their eyes open for tell-tale symptoms of the disease.

Gordon Donaldson, for the Commission’s team in Cowal & Trossachs, said;

“This disease has been making itself felt in the north and west - and although these areas haven’t been as badly hit as Galloway, the impact is, none the less, highly damaging.

“It can kill infected larch trees very quickly. Its impact is most obvious in amenity areas, but larch timber has commercial uses and the disease can therefore also have a harmful economic impact. Within a season, it can destroy decades of effort from foresters and that’s heartbreaking.

“The only way of tackling it is to reduce its rate of spread and this is best done by observing good biosecurity – cleaning mud off boots, tyres and pets before going to visit woodland – because dirt can carry these diseases from one place to another. We can also reduce the rate of spread by felling diseased trees as soon as possible to prevent the release of spores high up in the canopy as these can then be carried to other woodlands in the air and water.

“Unfortunately, these are the only practical ways of dealing with this disease and the more quickly that infected trees are felled the better our chances of keeping other forests healthier for longer. That’s why we’re asking that people keep their eyes open and report - as quickly as possible - any larch trees that look unhealthy this summer.”

Anyone spotting larch trees that they think might be infected should report their findings via the Tree Alert facility on the Forestry Commission website.

Symptoms of the disease on trees include lesions which exude dark fluid from infected bark, this then drying  to a crust on the trunk with discoloured, dying bark tissue underneath. Shoots and foliage on larch can also be affected, this being visible as wilted, withered shoot tips with blackened needles which are shed prematurely.

Trees with branch dieback can have numerous resinous ‘cankers’ on the branches and upper trunk, this often killing the entire branch and leading to distinctive ‘orangeing’ and browning of the foliage in the process.Although it does not usually kill ‘host plants’ such as rhododendron, viburnum, pieris and camellia, these plants will exhibit leaf-blackening, wilted shoots and die-back if infected. Some of these ‘foliar hosts’ can also generate many spores, which, in sufficient numbers, can then infect the bark of certain tree species.

Notes to editors

  1. Forestry Commission Scotland is part of the Scottish Government's Environment and Forestry Directorate.
  2. Tha FCS pàirt de Bhuidheann-Stiùiridh Àrainneachd is Coilltearachd aig Riaghaltas na h-Alba; a' riaghladh nan 660,000 heactairean ann an Oighreachd na Coille Nàiseanta, a' dìon, a' cumail smachd air, agus a' leudachadh choilltean gus buannachdan a choileanadh dha coimhearsnachdan, dhan eaconamaidh agus ag obair an aghaidh atharrachadh sa ghnàth-shìde.
  3. Media enquiries to Paul Munro, Forestry Commission Scotland press office, 0300 067 6507 / 07785 527590 / This email address is being protected from spambots. You need JavaScript enabled to view it.