I was excited to hear from a close relative that there has now been progress on developing elm tree saplings which could be resistant to Dutch Elm disease. As one who grew up in the 1970s I remember their loss over a few years as a result of the disease. For others they will be familiar from old photographs, poems, and paintings, yet they are strangely absent from today’s countryside. Dutch elm disease [DED] reshaped the nation’s woodlands and hedgerows, killing an estimated 25 million mature trees and altering landscapes that had developed over centuries. But the story isn’t over. A new generation of disease-resistant elm cultivars is beginning to change what’s possible for UK woodlands, conservation projects, and even urban tree-planting schemes. These elms are not the fragile giants of mid-century memory; they are carefully developed hybrids bred for resilience, longevity and ecological value. Their return opens up exciting potential for forestry, the countryside, wildlife recovery and long-term legacy forestry planning. What resistant elms could do for UK forestry [caption id="attachment_18575" align="alignleft" width="254"] Leaf of Elm[/caption] The forestry sector in the UK is under pressure to diversify tree species, increase resilience to climate change and pests, and expand woodland cover at scale. Disease-resistant elms present a genuine opportunity to contribute to those objectives. Elm is a fast-growing hardwood, historically valued for its tough, interlocking grain and durability when wet. While its traditional uses in wheel hubs, shipbuilding, coffins and farm structures may no longer drive demand, elm still has a place in modern forestry. The new resistant cultivars grow straight, tolerate a range of soils and are adaptable to urban, lowland and upland conditions. From a silvicultural perspective, introducing resilient elm back into mixed woodlands broadens the species portfolio at a time when ash dieback, Phytophthora strains and climate stresses are reducing the reliability of formerly dominant species. A more diverse woodland structure is a more resilient one — less vulnerable to the next big pathogen or extreme weather event. Elm trees also provide excellent early canopy cover and can integrate well into long rotation plans. For foresters thinking 50 to 100 years ahead, resistant elms offer the possibility of establishing stands that can thrive well into the next century. How reintroducing elms could transform the UK landscape The cultural loss of the elm is written into the character of the British landscape. Country lanes once lined with towering cathedral-like trunks became visually bare within a generation. Many regions saw hedgerows thinned and their organic shapes lost. Even in towns and cities, the elm had been a dependable street tree until Dutch Elm Disease [DED] stripped avenues of their distinctive silhouettes. [caption id="attachment_18572" align="alignleft" width="225"] Young Elm[/caption] Restoring resistant elms has the potential to bring back this visual richness. Their broad crowns, sculptural forms and strong architectural presence offer something different from oaks, beeches, horse chestnuts and maples. Landscapes shaped by elms have a softness and particular grace — an interplay of height and curve that many native-focused designers have long missed. Imagine the patchwork of English lowlands stitched again with lines of elms along watercourses. Picture Scottish or Welsh farmland bordered by hedgerows reinstated with elm that can survive more than a decade or two. The return of elms isn’t just ecological; it’s aesthetic, historical and emotional. It reconnects the modern countryside with an older Britain — restoring depth to the rural identity we sometimes forget is still evolving. Even urban design also stands to benefit. Many of the resistant cultivars withstand pollution, road salt, and compacted soils, making them excellent candidates for street avenues, civic squares and parks. A walkable city framed by elms once again feels completely plausible. Why disease-resistant elms might be good news for wildlife Elms have always been wildlife trees. Their leaves, seeds and bark host a wide range of invertebrates, which in turn support birds and small mammals. But perhaps the most striking ecological story is the elm’s role as a critical food plant for the White-letter Hairstreak butterfly.  This butterfly suffered a devastating decline as DED wiped out its primary larval host. Now, with resistant elms returning to woodlands, parks and village greens, conservationists have begun to integrate these cultivars directly into habitat recovery plans. Early evidence suggests that several resistant elm varieties are fully acceptable host plants, capable of sustaining healthy White-letter Hairstreak populations. Bird species also benefit. Elms provide dense cover and good nesting structure, and their early leaf flush is valuable for spring caterpillar availability — an important food source for breeding birds. In broader woodland planning, elm reintroduction helps to restore vertical layering and structural complexity, both essential for biodiversity. Combined with native shrubs and other hardwood species, resistant elms can contribute to dynamic ecosystems rather than monocultures. UK suppliers offering disease-resistant elms If you’re interested in planting some yourself — whether for a large woodland project or a small-scale tree-planting scheme — there are now some UK suppliers currently offering disease-resistant elm cultivars. One of them is Hillier Nurseries (Hampshire), one of the main UK distributors of the Resista® range, including Ulmus ‘New Horizon’ and Ulmus ‘Rebona’. These cultivars are widely used in both landscape and urban environments. Their website is at www.hillier.co.uk I plan to plant a few in the Spring and see how they get on.

I was born in the 1950s, a time when black smudges began to appear mysteriously on the trunks of sycamores in Britain. The culprit: sooty bark disease, a fungal infection caused by Cryptostroma corticale. Back then, I had no idea my life would unfold alongside a slow but steady parade of arboreal afflictions. But looking back now, I can measure the years not just in milestones and birthdays—but in the trees we lost along the way. Sooty bark disease doesn’t get the headlines these days, but it was a grim marker of post-war environmental change. Sycamores, long naturalised in Britain, would suddenly wilt and die, the bark flaking away to reveal a sinister black fungus. We didn’t yet understand how much stress—particularly from the hot, dry summers of the 1950s—played into its spread. It was an early sign: a warning that trees are far more vulnerable than they seem. Then came the true giant of tree diseases: Dutch elm disease. It began making headlines in Britain in the late 1960s and ravaged the landscape through the 1970s and '80s. Caused by a fungus (Ophiostoma novo-ulmi) spread by elm bark beetles, this pandemic decimated the native elm population. It’s estimated that over 25 million elms were killed in the UK alone. I remember the shift in the landscape. Once-common elm-lined avenues and hedgerows simply disappeared. As a child, I’d climbed elms in the park; as a young adult, I watched them vanish almost overnight. Dutch elm disease wasn’t just a biological tragedy—it was a cultural one. It marked a turning point, an awakening to the vulnerability of our treescapes. The decades ticked by. Chestnut trees became a familiar sight in my children’s drawings. But by the 2000s, I noticed the conkers looked smaller, sadder. Bleeding canker of horse chestnut, caused by Pseudomonas syringae pv. aesculi, began spreading rapidly across the UK. It causes a sticky, rust-coloured ooze from the bark and often leads to dieback and death. The disease didn't just affect the health of the trees; it diminished a cultural icon—conker tournaments and autumn walks lost something in its slow assault. Around the same time, sudden oak death (Phytophthora ramorum) emerged, though it affects more than just oaks. First identified in the US in the 1990s, it reached the UK in the early 2000s, causing widespread concern in woodlands and nurseries. It targets a range of species including rhododendrons, larches, and beech. The name alone—sudden oak death—carried a dramatic finality. Then came perhaps the most alarming of all in my later years: ash dieback, or Hymenoscyphus fraxineus. First identified in Poland in the 1990s, it reached the UK in 2012. It’s a true scourge, expected to kill up to 80% of the UK’s ash trees. These aren’t just forest trees—they line our roads, dominate hedgerows, shade our back gardens. Their decline feels intimate. Walking in ash woodland today is like passing through a ghost forest. The signs are unmistakable: leaf loss, crown dieback, diamond-shaped lesions. I’ve watched entire copses hollow out over just a few seasons. The cost is measured not only in timber or beauty, but in ecological networks—over 1,000 species depend on ash. And let’s not forget the oak processionary moth, which first arrived in the UK via imported oak trees in 2005. While not a disease in the fungal sense, it’s a threat nonetheless. Its caterpillars strip leaves and their tiny hairs can trigger allergic reactions in humans and animals. Forestry teams now issue warnings during their seasonal outbreaks. Oaks have stood proud for centuries, but even they are not safe anymore. There are others: sweet chestnut blight, plane wilt, the pine processionary moth, and new strains of Phytophthora that attack multiple species. The list gets longer, not shorter. So what’s going on? Part of the answer is globalisation. Trees, soil, and ornamental plants now travel easily between continents, bringing pathogens with them. Climate change plays its role too—stressed trees are more vulnerable, and warmer conditions allow pests and diseases to thrive. And while tree diseases aren’t new, our ecosystems today are more fragmented and less resilient. [caption id="attachment_8120" align="alignleft" width="400"] Leaf miner in Horse Chestnut[/caption]   What strikes me most, looking back, is how predictable this pattern has become. Every decade or so, a new name enters our vocabulary. Each time, we scramble to learn its symptoms, its vectors, its likely victims. And each time, the outcome is similar: loss, adaptation, then a wary lull before the next wave. Measuring my life in tree diseases might sound grim—but it’s also grounding. Trees are long-lived beings; their suffering unfolds slowly, deliberately. Watching them struggle is a reminder that the natural world is neither invincible nor immune to human action. The next great tree crisis is likely already on its way. But perhaps with better biosecurity, international cooperation, and public awareness, we can at least slow the tide. For me, though, the trees I’ve known—and the diseases that marked their passing—will always be a living calendar. A record of change, and of resilience.    

Recently, I met up with Nicola Spence, the UK's Chief Plant Health Officer: her observations took me on a hair-raising tour of the battlements that keep British trees safe from foreign invaders. To give an idea of the importance of plant health she pointed out that in the 1960s and 1970s Dutch Elm Disease from Europe killed between 10 and 20 million trees; the recent Ash Dieback (Hymenoscyphus fraxineus), which also came from continental Europe, is in the process of wiping out about 80% of the UK's ash trees. Consequently her department is very vigilant to stop any further invasions of pathogens or insects that could attack our trees. For example Defra and the Forestry Commission have successfully dealt with localised outbreaks of Sweet chestnut blight and in Kent there was a recent infestation of trees by the Asian Longhorn Beetle which meant cutting down and incinerating all trees within a 100 metre radius. Read more...

I met up with George Peterken, the man who has probably done more than any living person to protect Britain's ancient Woodlands.  He continues to study woods in fine detail to find out how they actually work and he has written a new book, "Woodland Development" where he explains how a 70-year study of Lady Park Woodland in the Wye Valley has revealed detail on how a broadleaved woodland develops.  Young trees that are just slightly larger than others at the beginning tend to stay larger: "within the first decade, probably sooner, those which are destined to become big trees will have already established themselves as the larger saplings - it's like the boat race: getting an early lead means you probably win in the long run."   Read more...

National Tree Week is approaching;  it is organised by The Tree Council.  This year, it runs from the 26th November to the 4th December.  This year's poster for the week is the headline image (opposite) *. The main aim of the week is to encourage the planting of trees.  Tree planting is important as many of our trees are now under threat, for example, bleeding canker and the leaf miner moth can attack Horse Chestnut, whilst the Ash is succumbing to Ash Dieback (Chalara). Read more...

When I last saw Oliver Rackham I was infected by his curiosity.  Someone suggested, as we walked though a woodland, that one spot might have been historically used for making charcoal so Dr Rackham dived into the undergrowth armed only with a set of keys and dug into the soil and he soon emerged triumphant with some old charred remains, proving definitively that this location had in fact been used for charcoal making.  This sort of curiosity and dogged ferreting for facts runs through his new book on the ash tree.  He considers what threats the ash tree faces, but he also uses the book as a platform for a wider diagnosis of the state of British woodlands.   Read more...