More than a decade after Chalara ash dieback was first confirmed in Britain, the disease is still quietly redrawing the treescape of the North West. Along the wooded valleys that run out of Stockport towards the High Peak, in the hedgerows of the Cheshire plain and in the back gardens of Marple, Bramhall and Hazel Grove, ash trees that once seemed permanent are thinning at the crown, dropping dead branches and, in the worst cases, being taken down before they fall on their own.
The disease has not produced a single dramatic moment. Instead it has become a steady background pressure on councils, landowners, woodland managers and the tree surgery firms that serve them. It has changed which trees are inspected, how often they are looked at, how they are dismantled when the time comes, what happens to the timber afterwards and what is planted in the space left behind. For a region with an unusually rich stock of mature garden and street trees, the consequences are being felt one tree at a time.
A disease that arrived slowly and stayed
Chalara ash dieback is caused by the fungus Hymenoscyphus fraxineus, which originated in East Asia and spread across mainland Europe before it was identified in the United Kingdom in 2012. Its spores travel on the wind from tiny fruiting bodies that develop on fallen ash leaf stalks in the summer, which is why the disease has been able to move through the countryside even where no infected plants were ever brought in.
Once a tree is infected the fungus blocks the water transport system in the shoots, causing leaves to wilt and blacken and branches to die back from the tips. Young trees can succumb in a few seasons. Older, larger trees tend to decline more gradually, often over many years, and some individuals show a degree of tolerance that has become the focus of long-term breeding and conservation efforts. Forest scientists expect a large proportion of the country’s ash to be lost over time, though the pace and severity vary enormously from one site to the next.
Because ash is one of the most common native trees in Britain, and because it grows readily in hedgerows, on railway embankments, along river banks and in gardens, the disease touches almost every landscape in the North West. The management response has had to be equally broad.
Recognising the symptoms
The early signs are subtle and easy to miss during the leafless months, which is one reason so many infections go unnoticed until a tree is clearly in trouble. Arborists and woodland officers typically look for a recognisable set of indicators, usually assessed in summer when the tree is in full leaf.
- Leaves that wilt, turn dark brown or black and hang on the shoot rather than dropping cleanly.
- Dieback of shoots and twigs at the outer edge of the crown, giving the tree a ragged, thinning silhouette.
- Diamond-shaped or elongated lesions on the bark where a dead side shoot meets a living branch, often with a purplish or brown discolouration of the wood underneath.
- Bushy clusters of new shoots, known as epicormic growth, sprouting from the trunk and main limbs as the tree tries to compensate for lost foliage.
- In later stages, dead wood throughout the upper crown and secondary infections at the base of the trunk that can undermine the tree’s stability.
None of these signs is unique to ash dieback on its own. Drought stress, root damage and other pathogens can produce similar symptoms, and a proper assessment weighs the overall pattern rather than one feature in isolation. That assessment is increasingly the first step in any decision about an ash tree, whether it stands in a public park or a private garden.
Why infected ash has changed the way trees are taken down
The most significant practical consequence of the disease for the tree care trade has been a change in how affected trees are worked on. Healthy ash is a strong, flexible timber, which is exactly why it was traditionally used for tool handles and sports equipment. Ash weakened by dieback is a different material altogether. As the fungus and the secondary decay organisms that follow it progress, the wood becomes brittle and unpredictable. Branches that look sound can snap under a climber’s weight, and anchor points that would normally be trusted cannot be relied on.
For that reason, professional guidance has moved firmly towards avoiding climbing badly affected ash wherever possible. Firms now favour working from the ground, from a mobile elevated platform or by dismantling the tree in sections using rigging systems that lower each piece under control. Sectional dismantling, once reserved mainly for trees hemmed in by buildings, conservatories and greenhouses, has become routine on declining ash even in open ground, because the alternative of felling a brittle tree in one piece is difficult to control.
A qualified Tree Surgeon carrying out this kind of work will normally hold NPTC certificates for the chainsaw and aerial tasks involved, work to BS 3998, the British Standard that sets out good practice for tree work, and carry public liability insurance at a level appropriate to the risk. Ash dieback has made those credentials more important rather than less, because the margin for error on a decayed tree is far smaller than on a healthy one. The trade has also had to reckon with the sheer volume of work: the disease is producing a steady flow of removals across the region at the same time as the ordinary demand for pruning and hedge maintenance continues.
Not every infected ash needs to come down
One of the more encouraging shifts in recent years has been a move away from pre-emptive clearance towards a more measured, tree-by-tree approach. Woodland managers and arborists increasingly stress that an infected ash is not automatically a dangerous ash. A tree with early symptoms standing well away from paths, roads and buildings may be left to see how it fares, both because it poses little risk and because trees that show tolerance are valuable to the future of the species.
The decision to remove tends to rest on a combination of factors: the proportion of the crown that has died, the presence of basal lesions or fungal brackets that suggest structural decay, and above all the target, meaning what or who would be harmed if the tree or part of it failed. An ash overhanging a busy pavement or a neighbour’s roof is judged very differently from one at the bottom of a paddock. Regular monitoring, typically an annual look during the summer, allows owners to intervene before a tree becomes hazardous without removing trees that still have years of life and habitat value in them.
Where a tree is protected by a Tree Preservation Order, or stands in a conservation area, the usual rules still apply. Consent from the council is needed before work on a tree covered by a TPO, and the council must be given six weeks’ notice of proposed work in a conservation area. There are exemptions for trees that are dead or present an immediate danger, but the exact process and the evidence required vary, and property owners are generally advised to check with the local council or its planning portal before any cutting begins.
Wildlife-aware tree work in a changing landscape
Ash dieback is playing out in a landscape that is also under pressure from habitat loss, and the way affected trees are managed has consequences well beyond the tree itself. Ash supports a wide community of lichens, mosses, insects and birds, and mature or declining trees with cavities and dead limbs are often the most valuable of all for wildlife, including bats. This has pushed responsible operators to treat every job as an ecological question as well as a safety one.
The legal position on birds is clear and applies to every tree and hedge in the country. All wild birds, their active nests and their eggs are protected under the Wildlife and Countryside Act 1981. Tree and hedge work should avoid the main nesting season, which runs roughly from March to August, unless a careful check confirms there are no active nests present. Larger-scale work, and any work on trees with features that might shelter roosting bats, may need to consider protected species more formally before it goes ahead.
In practice this means a good tree surgery firm builds wildlife checks into its routine. Some, including North Cheshire Forestry, a family firm based in Marple that has worked across Stockport, South Manchester and the High Peak since it was established in 1976, operate a strict non-interference policy for nesting birds as part of a written environmental policy. Where a nest is found, work on that part of the tree stops and is rescheduled. Where possible, dead standing wood that poses no risk is retained as habitat, and felled sections may be left as log piles rather than being carted away.
What happens to the wood
The volume of ash timber now coming out of the region’s gardens and woodlands has focused attention on what happens to it afterwards. The environmentally preferable options are well established even if they are not always followed. Brash and smaller branches are typically chipped on site, with the chip used as mulch on borders and paths or taken away for composting and biomass. Larger sections can be milled, sold as firewood once seasoned, or left in place as deadwood habitat.
Firms with an environmental policy generally commit to recycling the wood they remove rather than sending it to landfill. That matters in the context of ash dieback because the sheer quantity of material involved would otherwise represent a significant waste stream. Homeowners arranging removals are increasingly asking what will become of the timber, and the answer is a reasonable indicator of how seriously a contractor takes the wider environmental picture. The management of infected leaf litter is a separate consideration; because the fungus sporulates from fallen leaf stalks, some site managers choose to collect and compost leaves at high temperature or leave them where they lie away from young ash, but there is no simple rule that suits every situation.
Replanting after removal
Perhaps the most important long-term question raised by ash dieback is what replaces the trees that are lost. A removed ash leaves not only a gap in the canopy but a stump and a root system that, if left, will either resprout or slowly decay and prevent anything else being established in the same spot. Stump grinding that takes out the root bowl rather than just the visible stump is increasingly specified precisely because it makes replanting possible in the same location, which is often the only sensible place for a replacement tree in a small garden.
The advice from woodland and horticultural bodies is consistent: plant a diverse mix of species rather than replacing like with like. Relying heavily on a single species is what made the ash losses so painful, and a garden or hedgerow that contains oak, field maple, hornbeam, rowan, birch, wild cherry and hawthorn is far more resilient to the next disease or pest than one dominated by any one of them. In garden settings, smaller native and ornamental species that will not outgrow their space are often the more practical choice.
Timing and aftercare matter as much as species choice. Bare-root planting in the dormant season, protection from rabbits and strimmers, and regular watering in the first two or three summers give a young tree the best chance. Firms such as North Cheshire Forestry are increasingly asked to advise on what to plant as part of a removal job, an indication that property owners see the loss of an ash as the start of a new planting rather than simply the end of an old tree.
The long view
Ash dieback will continue to shape the North West’s woodlands, hedgerows and gardens for decades. Some trees will prove tolerant and survive; many will not. The region’s response, from local authorities running inspection programmes to individual homeowners deciding what to do about the ash at the bottom of the garden, is gradually settling into a pattern that balances safety with restraint.
The firms doing the work have adapted accordingly. Established local operators with NPTC-certified staff, work carried out to BS 3998 and public liability cover of up to five million pounds are handling a steady flow of assessments, sectional dismantlings and replanting jobs, often for customers who have never had to think about tree disease before. That combination of technical care, respect for wildlife and a commitment to putting something back is, for now, the closest thing the region has to a strategy for living with a disease that is not going away.
