It Doesn't Seem Real Until it Happens to You

Yes, folks, it finally happened to us. We had a good run, but the dieback got us, right in the Bridgwater Road, which will be closed for five days this October to take down infected Ash trees.

Ash saplings infected by the Chalara fraxinea fungus were found at Buckingham Nurseries at the beginning of 2012.

Here is the first known selfie of the Ash dieback fungus formerly known as Chalara fraxinea or Hymenoscyphus pseudoalbidus: Hymenoscyphus fraxineus.

Back in 2012, the concern was that this plague, which creeps inexorably through air, soil, and aboard insects, would pierce our beloved Common Ash in leaf and stem, leaving no survivors.

Of all the trees, that grew so fair…

But in 2024, there's good news: Chalara / Hymenoscyphus (which only affects Common Ash, Fraxinus excelsior, not any other tree, including Mountain Ash, which is the unrelated Sorbus aucuparia) is not a methodical assassin.

Ash trees have varying degrees of resistance: many do die, but many are only scorched, losing limbs while the rest of the tree carries on.

Some mature trees only experience partial die back, and then recover in other places, although none seem to be immune.
Trees in woodland seem more susceptible, while trees out by themselves in the open, or in urban areas with no bare soil around and fungicidal, dry, polluted air seem to be much less affected.

So, while Ash is going to decline (and cost a lot of money tidying up in the process), it isn't going extinct just yet, and should be much less affected than Elms were by Dutch Elm Disease.

Management of Ash Die Back is in full swing, you'll find everything you need here on the Gov website, with specific advice for people who just own one or a few ash trees, and for people managing Ash woodland.

From the University of Vienna, we have a 240p potato-quality video of the release of fungal spores from ash twigs infected with the reproductive stage, which was originally named Chalara fraxinea, since updated to Hymenoscyphus fraxineus.

It was filmed in 2012, so that's why it looks like it was filmed in 2006.

Back in 2012, we were fortunate to talk with tree experts at the Institute of Forest Entomology, Forest Pathology and Forest Protection, IFFF. They shared the images below with us, and we spoke about doing what we can to sensibly limit the spread of the disease. A mad rush to deforest Ash could remove genetically resistant trees, and interbreeding those trees is the key to resistant Ash populations in the future.
If all goes well, it could be possibly to re-introduce highly resistant Ash trees in the future.

Ash tree dieback disease images

Images include microscopic images of the pathogen, lab-grown fungal cultures, branch and stem lesions, leaf wilt, and crown dieback.

Diseased leaves, twigs and branches eventually fall to the floor, setting the scene for the reproductive stage of the fungus – a trumpet-shaped mushroom

Cultures of the fungus, grown for research purposes at the IFFF in Vienna.

How to Identify Ash Die Back Disease

A tell-tale sign of ash dieback disease is a necrotic lesion (tissue death) on stems, twigs and branches:

Once the fungal infection spreads fully across a stem or branch, nutrition is cut off beyond that point and leaves begin to wilt and die.

Continued leaf loss works its way back towards the trunk of the ash tree:

Cross-sections of dead wood show how far into the trunk necrotic lesions can reach

Has ash dieback disease come to your area?

Image credits: By kind permission of Thomas Kirisits, Josef Wampl, Christian Freinschlag, Katharina Kräutler and Michaela Matlakova of the Institute of Forest Entomology, Forest Pathology and Forest Protection (IFFF), Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna (BOKU), Vienna, Austria