Chalara Dieback of Ash on my doorstep

Living in rural North Yorkshire, on the border with the East Riding, provides easy access to beautiful areas of the Wolds, Howardian Hills, Moors and coastal regions for country walks.

As a Plant Pathologist, it’s a fascinating place to live – being in the front line of the spread of Chalara Dieback of Ash. When going out for regular walks, I now find journey times much slower as I stop to survey for Chalara.

Tell tale signs

Now is an excellent time to look for symptoms. Without significant undergrowth getting close to young ash, regeneration growth and characteristic stem lesions are easier to spot without too many leaves.

From my experience, the most reliable and consistent symptom is the slightly sunken, foxy red-brown lesion centred on a side branch. This frequently causes the death of the leader, resulting in a flush of side shoots at the base as the tenacious ash tries to recover.

Not as easy as it seems

Even I’ve been fooled on several occasions in thinking that lower shoot dieback is due to Chalara. But this is frequently down to light starvation – looking for stem lesions is the key.

When I think I may have found Chalara I always enjoy trying to find the tiny ‘mushroom like’ fruiting bodies of the sexual state on fallen rachis. To date, I have only seen them once but they’re worth the hunt.

There are several new Chalara records quite close to my home which I’ve reported through Tree Alert so I’m constantly looking to see if it’s arrived in my village (check out the 10km Chalara distribution map for your local area). In my back garden I’ve allowed a self seeded ash to flourish hoping it will act as a sentinel tree.

Now’s the time to keep your eyes peeled!

The one area I’ve struggled with is recognising symptoms on mature trees. Talking to my local Forestry Commission Tree Health Officer, Alan Ockenden, about this problem he recommended looking at foliage for signs of wilting in late June and early July. If he sees suspicious symptoms he’ll check on regrowth and hedgerows, which are easier to see and sample.

Beware the tree whacking man

Personally, I don’t take the easy option. So when I’m trying to bring down leaves I can’t reach to take a closer look, I’ve found my walking pole a useful aid – although I may look a little odd whacking a tree in the middle of nowhere!

So if there’s one message to take away from all this, it’s that now’s a great time to be out and about looking for Chalara. Happy hunting!