Once the hallmark of a rural idyll, our English elms were almost eradicated by the devastating fungal infection of Dutch Elm Disease. Thankfully a new cultivation aims to secure their survival, as Andrew Martin explains.
Perhaps more so than any other feature, the English landscape is characterised by its trees. It’s the impenetrable thickets of blackthorn and hawthorn, billowing with delicate spring blossom. The solitary veteran oaks, punctuating graceful parklands with their ancient, crooked boughs. The formal majesty of an avenue of purposeful limes. Then, there are the innumerable street trees — the quiet sentinels of our villages and towns. Together, these eclectic individuals make up the fabric of the modern British landscape, as they have done for millennia. In more recent times, however, there has been one irrevocable omission: devastated by disease, our elms have all but disappeared.
Within living memory, so many of our hedgerows, lanes and parks were awash with elm trees. Several varieties once thrived here, but it’s the eponymous English elm (Ulmus minor ‘Atinia’ — thought to have been introduced by the Romans about 2,000 years ago) that often carries the most weight in the collective national memory. Those that remember them recall graceful giants, often exceeding 100ft in height, casting a vast, deep shade in their wake. Upon reaching the full greatness of maturity, the English elm was long admired for its figure-of-eight form, its lower canopy tapering inwards to create the narrow ‘waist’ of the tree, before erupting outwards again at the top.
For centuries, the elm was a mainstay of folklore and art. Somewhat ominously, given its eventual fate, it also had the undesirable association of death, its water-resistant qualities making it a favoured choice for coffin wood. Yet those with an artistic eye were enamoured with it. Few more so than John Constable, who would immortalise the distinctive beauty of mature elm within The Hay Wain, an artwork that for many of us remains the definitive image of rural England. Undeniably, these trees always possessed the power to captivate and inspire, but it wasn’t to last.
As the 20th century began, dark clouds were gathering over the much-lauded elm. Disease broke out after 1910, eliminating an estimated 10%–40% of the trees, before petering out by 1945.
The tell-tale tunnel boring tracks of Elm Bark Beetle — aka Scolytus beetle — which introduces the fungus Ophiostoma ulmi that infects the tree with Dutch Elm Disease, DED.
In the 1960s, however, the pathogen known as Dutch elm disease (DED) returned with a cruel vengeance, imported within a consignment of logs from North America. The consequences were nothing short of catastrophic; in Britain alone, 25 million mature elms succumbed to the disease directly or were pulled down in an attempt to inhibit its spread.
Dutch Elm Disease: The Timeline
- 1910–45
First Dutch elm disease epidemic - 1960–64
Second epidemic commences - 1973
Elm breeding programme begins at Istituto per la Protezione delle Piante (IPP), Florence, Italy - 2014
Dr David Herling acquires IPP-produced elm ‘FL493’, hybridising it with a field elm from Kent and naming it ‘Wingham’ - 2019
Disease-resistant hybrid ‘Wingham’ elms become commercially available in Britain
Since DED took hold, carried by the Scolytus beetle that breeds beneath the bark, there have been attempts to preserve and reinstate these iconic trees. An intensive management scheme in Brighton has allowed about 17,000 elms to hang on in the city, the only ‘significant population of elms surviving in Britain today’, according to the local council. However, they have had a precarious existence; a DED outbreak in 2015 claimed 14 mature trees. Some innovative science was called for to secure fully the future of the elm.
Planted by Charles II, felled in 1943: diseased elms in the Long Walk at Windsor, Berkshire.
Arguably, the loss of elm was mourned by none more than by Dr David Herling, who became determined to ensure that the tree wouldn’t be consigned to memory. Having witnessed the destruction wrought by Dutch elm disease first hand, he would go on to dedicate much of his life to reviving the species. Herling, together with his childhood friend Fergus Poncia, acquired an elm variety bred by Italian researchers and crossed it with an existing field elm (Ulmus minor) found at Tonge Mill, near Sittingbourne in Kent, to produce a unique hybrid.
By cultivating hybrid trees, the hope is to take the naturally disease-resistant characteristics of elms growing across the globe and combine these with more familiar species found closer to home, creating offspring that look — and perform — much like the trees we used to know. The result of their efforts is Ulmus x ‘Wingham’ — the ‘Wingham’ hybrid elm — named after the village where Herling first grew them. Sadly, Herling died in 2020, just as his work seemed to be reaching fruition, but the foundations to fulfil his vision had been set and research continues.
Richard Buggs, who is studying 50 of Herling and Mr Poncia’s elms as Kew’s senior research leader, says that the four best of these hybrids have ‘performed well under testing for resistance, but only time will tell how they do in the longer term’. Elms generally only become attractive to the Scolytus beetle once reaching a certain size, meaning many can appear to grow healthily for several years before beginning to show the signs of infection. ‘As a tree has to be more than 12 years old to become fully exposed to the disease, field testing is a long process,’ explains Prof Buggs. His research is now looking to identify the parts of a tree’s DNA that confer resistance to DED, which could help with future breeding programmes.
One of the ‘Preston Park Twins’ in Brighton, the largest surviving elm trees in the UK.
‘The 50 offspring vary greatly in their resistance to Dutch elm disease and this allows us to try to find parts of the genome that are present in resistant trees, but absent in susceptible trees,’ Prof Buggs adds. For those who loved the sight of the traditional English elm, these hybrids may not exactly replicate their form, but ‘it is hoped they may resemble it’.
A separate trial led by Andrew Brookes of the charity Butterfly Conservation is raising several other varieties of hybrid elm, produced across Europe, to examine their suitability for growing in Britain. He hopes, in particular, to discover if they are a viable host for the rare white-letter hairstreak butterfly, which, due to its reliance on elm to complete its lifecycle, has declined by 78%, as the majority of these trees vanished from our shores in the 1970s.
American hybrid Ulmus ‘New Horizon’ re-creates the lost elm avenue at Pontcanna Fields, Cardiff.
A recent scheme in the North of England encouraged the public to purchase and plant ‘Wingham’ saplings to benefit the species. Ben Keywood, entomologist at the Sheffield and Rotherham Wildlife Trust, who ran the project with local environmental group Nether Edge and Sharrow Sustainable Transformation (NESST), says that ‘in terms of strong habitat for species such as the white-letter hairstreak butterfly, we envisage it could take some time to establish — perhaps 10–20 years in some cases’. He adds that ‘it would be great to see similar schemes to re-establish elm across the country, where appropriate to do so’.
By early 2024, the population of elms believed to be disease-resistant in Sheffield had been increased from a mere four to 76. For now, the ‘Wingham’ elm has provided a much-needed injection of optimism for those determined to see these trees return. Patience and caution are required, but projects are under way and making the first steady steps. Before its untimely demise, elm had enjoyed a long history in this island that we call home; now, more so than at any other point in the past 50 years, there’s real hope that it may have a future here, too.
