Ash trees are a defining feature of Devon and Cornwall’s landscape — lining Devon’s sunken lanes, sheltering Cornish farmsteads, and filling the wet valleys of both counties with their distinctive, feathery canopy. The arrival of Hymenoscyphus fraxineus — ash dieback — is a genuine threat to this landscape and to anyone with ash trees near buildings, roads, or areas of regular use.
The situation in Devon and Cornwall
Ash dieback arrived in the South West later than in eastern England, but it is now established across both counties. The Forestry Commission estimates that around 80% of ash trees in the UK will eventually die from the disease. In Devon and Cornwall, where ash is particularly prevalent in the hedgerow and riparian landscape, the scale of the challenge is significant.
Signs of infection
Look for wilting or blackening of new growth in spring and early summer, starting at the shoot tips. Infected leaves curl and turn brown at the margins before dropping early. As the disease progresses, you will see die-back extending into larger branches, with characteristic diamond-shaped lesions at branch junctions where dead wood meets living tissue. In later stages, heavy epicormic (water-shoot) growth sprouts from the lower trunk as the tree attempts to compensate for crown loss above.
Why ash is particularly dangerous in decline
Ash is notoriously brittle compared to most other native species. A declining ash sheds branches in seemingly calm conditions, and its root system can fail faster than the visible above-ground decline suggests. An ash tree near a building, road, footpath, or any area of regular use that is showing signs of dieback should be assessed promptly — not watched from a distance while the situation develops.
Devon’s lane network: a particular concern
Devon’s characteristic sunken lanes are often lined with large ash trees growing on the tops of hedgebanks. These trees are typically old, often multi-stem, and frequently have a significant portion of their root system in shallow soil above the lane. Ash dieback in this setting creates a particular risk — trees that shed large branches or fail onto passing vehicles and pedestrians. If you are responsible for land alongside Devon lanes with ash trees, we would strongly recommend an inspection.
Acting early: the financial case
A standing ash tree in early decline can typically be felled in a straightforward operation at reasonable cost. The same tree in advanced decline — structurally compromised, with failed root anchorage, needing to be dismantled section by section from the top down — can cost three to five times as much to remove safely. If an ash has already failed and caused damage, the costs multiply further. The case for early assessment and action is overwhelming.
We carry out ash dieback assessments across Devon and Cornwall as part of our free site visit service. If you have ash trees that concern you, call us.