Work has begun at Westonbirt, The National Arboretum in Gloucestershire to fell 2000 ash trees infected with ash dieback.


The site's famous 200-acre Silk Wood is now closed with the work to remove the 2000 trees set to take four weeks.

And the work doesn't end there. In order to save further infection and future trees an estimated further 3000 trees infected with the fungal disease are set to be removed at a later date.

So what's gone wrong?

The problem is due to Chalara ash dieback, a serious disease of ash trees which is infecting ash trees across Europe and the UK. Chalara ash dieback spreads on the wind-borne spores of the fungus Hymenoscyphus fraxineus, and so there is little that can be done to prevent the spread of the disease.

Ash dieback was first seen at Westonbirt in 2015 and some trees were removed in 2019. The disease affects ash trees by blocking their water transport systems which in turn causes leaf loss, lesions in the bark and eventually leads to a dieback of the crown of the tree. After time the tree becomes brittle and will eventually collapse.

Westonbirt say that they have reached a pivitol moment in their management plan and that felling and future felling will be necessary to ensure the future health of their ancient woodland.

The felling of the infected ash trees will make way for new plantings of various species, which will help to create a resilient woodland.

An area 6.74ha in size will be completely felled and replanted, with a further 22.78ha undergoing the removal of dead or dying ash trees, aiding natural regeneration and allowing healthy species to grow

The Westonbirt team are keen to stress that this does not mean that the ash tree will be disappearing from Silk Wood. In some areas Fraxinus excelsior (known as European ash or common ash – which is most affected by Chalara ash dieback) will be retained to monitor the progression of the disease.

They also have 23 other exotic species of ash which will remain and be carefully monitored for tolerance to the disease. And there are encouraging signs that remaining native specimens are showing natural resistance to the disease and future generations should build a genetic resistance.

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Forestry England suggest that we all have a part to play in the prevention of the spread of pests and diseases and that we should follow the following simple measures:

Keep it clean: Pests and diseases can spread in the mud and debris on shoes, paws and tyres, so simple measures such as cleaning your boots and car wheels after a walk in the Forest can help to limit the spread of diseases.

Don’t risk it: Don’t bring any plant or tree products back from trips abroad, because these might be carrying harmful non-native tree pests or pathogens.

Be vigilant: Report any trees that you suspect are in ill-health to the Forestry Commission using Tree Alert


Join the Friends of Westonbirt Arboreum: Your membership donation goes directly back into maintaining Silk Wood and Westonbirt Arboretum for future generations.


Daniel GriffithsDigital Editor

Daniel Griffiths is a veteran journalist who has worked on some of the biggest home and entertainment brands in the world. He is a serial house-renovator and home improvement expert, taking on everything from interior design and DIY to landscape gardening and garden design.