Chalara dieback of Ash trees is caused by the Chalara fraxinea fungus. The chief signs are die back and lesions centred on dead side shoots.
Latest advice is to not fell prematurely to allow for regeneration of resistant strains.
Remove if more than 50 % of crown is dead. Help slow the spread by collecting or burying fallen ash leaves in autumn, as they are the primary source of fungal spores. Diseased trees by roadsides/footpaths should be removed for safety reasons.
Acute Oak Decline is a new disease which started some 20 – 30 years ago. It is considered a threat to long term health and survival of native oak species. It is spread by 2 bacteria and one insect species. At present it is in the Midlands and Welsh Borders. Mature trees are most affected.
Symptoms to look for:
1/ Weeping patches of dark fluid visible on oak stems
2/ Cracks in the outer bark from which fluid weeps
3/ Irregularly oval shaped lesions in the inner bark , and cavities behind outer bark around seepage point
Spread
Aerial mode of dispersal
Management
Prompt removal and destruction of the bark affected.
Exercise caution over moving firewood to locations where Acute Oak Decline is not present. Avoid moving firewood from symptomatic trees.
Suspected cases should be reported to the Forestry Commission Plant Health Service.
Tel. 0131 314 6414 or email plant.health@forestry.gsi.gov.uk.
West Hill Tree Warden – Eileen Perkins Tel 01404 815905