Wakehurst forced to close part of gardens in fight against deadly ash dieback disease

Wakehurst's gardens will remain open to visitors
Ten years since ash dieback was discovered in the UK, Wakehurst will close the Loder Valley, the most significant closure in its history, to carry out vital felling work
Kew scientists have developed genetic screens to predict ash tree survival, creating opportunity for accelerated ash breeding programme
Ash dieback is expected to kill up to 75% of ash trees across the country
RBG Kew hopes to preserve ash for the future through expert horticultural management, seed banking and pioneering scientific research

Experts at Wakehurst, Kew’s wild botanic garden in Sussex, are taking drastic action in the fight against ash dieback, the deadly fungus devastating the British countryside.

10 years since this disease was first discovered in the UK, the gardens near Haywards Heath have been forced to close a part of their site from early December, as the team embarks on a major felling operation in the Loder Valley Nature Reserve.

Diseased trees pose a risk to visitors and Wakehurst experts will be working across the 150-acre haven of wetlands, meadows and woodlands to prevent trees and branches from falling over public paths. Ash dieback is the most significant new tree disease to impact the UK in the last 60 years, and this is the first time Wakehurst has had to close such a considerable stretch of the gardens since opening as Kew’s sister site in 1965.

Ed Ikin, Director of Wakehurst said: “Recent extreme weather such as drought stress has only accelerated ash dieback’s spread. The closure of our nature reserve marks a pivotal moment in our history, as we fight this deadly disease, and serves as a reminder of how the work we undertake at Kew is critical to combat the twin threats of biodiversity loss and climate change.”

In order to understand and prevent this deadly fungus, which is set to kill up to 75% of ash trees in the UK, Wakehurst is bringing together a unique blend of horticulture and science in its 535-acre site. Over the past decade, tree surveys across the site conducted by the experienced Arboretum team have revealed over 90% of ash at Wakehurst had signs of ash dieback, including a reduced canopy, dark lesions in the trunk and blackened leaves.

Russell Croft, Arboretum Manager said: “We have already made strong progress removing infected ash trees from roadsides around Wakehurst, as well as other areas within the gardens. The safety of our visitors and staff is our priority, so it’s essential we reduce and prevent the signs of ash dieback in our woodlands. Due to the instability of the trees, this is dangerous but extremely vital work.”

Forestry work will be combined with the specialist knowledge of Kew scientists. With promising signs that some ash trees are tolerant to dieback, Wakehurst’s leading researchers are looking to generate a new population of resilient ash. Over the last decade, Professor Richard Buggs has been conducting pioneering studies to explore correlations between genetic variants in healthy and unhealthy ash trees. With data indicating that the health of trees can be predicted from their genomes, Kew is now exploring the possibility of an ash breeding scheme to help secure a future for the native tree species.

Professor Richard Buggs, Senior Research Leader (Plant Health) said: “There is currently no cure for ash dieback and it threatens to kill a vast quantity of ash trees in the UK. This will have a huge impact on the British landscape. Our new findings of natural resistance found in a small minority of British ash trees will help us to predict how ash populations will evolve under the threat of ash dieback. While many ash trees will die, our findings are encouraging from a long‐term perspective and reassure us that ash woodlands will one day flourish again.”

Scientists at the Millennium Seed Bank (MSB) at Wakehurst, home to the most important collection of genetically diverse ash seed, have also been conducting two further projects to conserve ash trees. Kew's UK tree seed collecting project Diversity, Adaptation and Use tackles the increasing threat of disease and climate change to trees, building on many years of work to bank seeds from genetically diverse collections of healthy trees and forms a vital resource for future generations.

Kew scientists are also contributing to the Living Ash Project, a collaboration between the Future Trees Trust, Fera, Forest Research and Kew, funded by Defra. In 2021, Kew scientists began a series of trials to improve ash propagation techniques using cuttings. If successful, the project could help produce and ultimately plant healthy ash in woodlands where much has been lost.

Ted Chapman, UK Conservation Partnerships Co-ordinator said: “A small proportion of trees have shown tolerance to ash dieback, so identifying and collecting seeds and other genetic material from these trees remains a priority for the Millennium Seed Bank (MSB). Our tree seed collecting project is one of the many initiatives Kew has launched to secure our planet’s future, contributing to the MSB’s vast collection, or what we like to call ‘the Noah’s ark for plants’.”

This combination of research and woodland management comes at an essential time, as the drastic degradation of ash trees poses a serious threat to woodland diversity. Ash is fundamental to a healthy ecosystem, providing multiple benefits to nature and society. Ash trees can adapt to different soils and climatic conditions, which has proven useful for major tree planting schemes, and are also home to a range of wildlife, meaning the team have a limited window in which to work, outside of key nesting periods. Ash dieback also presents a huge financial cost to British society, from the practical management of the disease to the loss of environmental services, it’s estimated to cost £15 billion.

The team at Wakehurst are ensuring that the woodlands will continue to thrive with this substantial removal. Where possible, fallen crowns and deadwood are left on the ground to encourage natural regeneration and the removal of canopies allows light to shine on the forest floor to stimulate new growth. Spaces created by removed trees will welcome new UK native species, grown in the Millennium Seed Bank nursery. In order to reduce waste and conserve the felled trunks, many have been manufactured into furniture, and chippings are being sold as renewable biomass or taken for charcoal burning onsite.

Work is expected to take several months. Updates on the Loder Valley will be shared on https://www.kew.org/wakehurst.

Through their contributions, Wakehurst members help to save UK landscapes and fund vital research on issues such as ash dieback.

ENDS

For more information, images and interviews please contact Jessica Hayne, Communications & Content Executive: j.hayne@kew.org

Notes to Editors

About Wakehurst

Please note that Wakehurst is referred to just as Wakehurst, not Wakehurst Place. It is not a National Trust property.

The National Trust was bequeathed the Mansion and grounds of Wakehurst in 1963. It was then entrusted to us here at Kew in 1965, and we now work in partnership with the National Trust to care for our collections and heritage areas.

Wakehurst is Kew’s wild botanic garden in the Sussex High Weald. Its ancient and beautiful landscapes span 535 acres and are a place for escape, exploration, tranquillity, and wonder. Its diverse collection of plants from Britain and around the globe thrive within a tapestry of innovative gardens, temperate woodlands, meadows, and wetlands. Wakehurst is a centre for UK biodiversity and global conservation, seed research and ecosystem science. At its heart is Kew’s Millennium Seed Bank, the world’s largest store of seeds from wild plant species.

RBG Kew receives approximately one third of its funding from Government through the Department for the Environment, Food and Rural Affairs (Defra) and research councils. Further funding needed to support RBG Kew’s vital work comes from donors, membership and commercial activity including ticket sales. In the first six months of 2022, Kew has welcomed over 10,000 visitors with a £1 ticket for those in receipt of Universal Credit, Pension Credit and Legacy Benefits.

About Kew Science

Kew Science is the driving force behind RBG Kew’s mission to understand and protect plants and fungi, for the well-being of people and the future of all life on Earth. Over 300 Kew scientists work with partners in more than 100 countries worldwide to halt biodiversity loss, uncover secrets of the natural world, and to conserve and restore the extraordinary diversity of plants and fungi. Kew’s lays out five scientific priorities to aid these goals: research into the protection of biodiversity through Ecosystem Stewardship, understanding the variety and evolution of traits in plants and fungi through Trait Diversity and Function; digitising and sharing tools to analyse Kew’s scientific collections through Digital Revolution; using new technologies to speed up the naming and characterisation of plants through Accelerated Taxonomy; and cultivating new scientific and commercial partnerships in the UK and globally through Enhanced Partnerships. One of Kew’s greatest international collaborations is the Millennium Seed Bank Partnership, which has to date stored more than 2.4 billion seeds of over 40,000 wild species of plants across the globe. In 2020, Kew scientists estimated in the State of the World’s Plants and Fungi report that 2 in 5 plants globally are threatened with extinction.