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13 messages
31/07/2014 at 22:48

My Rowan tree is showing signs that it may be dying. The leaves are starting to turn brown and the bark is splitting open on the trunk. Has anyone any ideas what is causing this? I had exactly the same problem with another about 3 years ago with the leaves not falling in the Autumn when they had totally turned brown and the bark on the trunk showed the same splitting. I had to resort to felling and replacing it.

31/07/2014 at 23:29
H Rowan-Mountain Ash Diseases

Healthy Mountain Ash trees are gorgeous specimens that can help brighten up even the most unattractive yards. However, the species is not immune to diseases that can rob it of its beauty and charm.

Among the most common infections that afflict the Mountain Ash tree include:

  • Cytospora Canker: This fungal disease targets the tree's trunk and branches by peppering it with brown, irregular shaped cankers. The ugly pimple-like masses can ooze and spread throughout the Mountain Ash. In severe case, the disease can kill the tree.
  • Fire Blight: This infection kills the tree's flowers and leaves. Symptoms include black leaves, brown flower clusters and spores that ooze slime and infect the tree's branches.
  • Leaf Spot: This shows as irregular, brown spots on leaves. If left untreated, tiny, black spores will form as well. Advance cases also cause leaves to drop prematurely.

Mountain Ash is also susceptible to sawflies which can defoliate the tree within a few days.

 Found the above while surfing and thought it might help you with a diagnosis!

01/08/2014 at 16:22

 This is what the leaves, berries and bark look like. Looks like it might be Leaf Spot plus something else. Anyone any ideas what it is and how to cure it?


01/08/2014 at 17:07

That splitting of the bark at the base of the tree looks extremely serious and possibly a sign of Honey fungus, unfortunately.  It would also explain why you recently lost another one.  Have a look at the RHS advice:


02/08/2014 at 12:14


Thanks for that. However, looking at the RHS link you sent me I don't think its Honey Fungus as there are no signs at the base of the tree and the splits in the bark go up to at lease 3m.

02/08/2014 at 13:19

Hi Magnum

You stated about your old trees `the leaves not falling in the autumn, that is a tell tale sign of fire blight this also causes splitting of the bark

The bark splitting is the tree trying to protect itself from disease

The tree above, could you go out with a sharp knife and take the bark off round the scar and tell me what colour the trunk is under the bark you have taken off and is it oozing pus


02/08/2014 at 13:20

It might be another form of fungus, Magnum.  Try poking a large screwdriver etc through one of the cracks in the bark into the heartwood of the tree.  It should be solid.  If it crumbles, then the heartwood is rotting and it will be terminal as the wood will have lost it's strength and the tree will be prone to being blown down by the wind, or branches may fall under their own weight, making it dangerous.  Have a good sniff through the cracks too - any hint of a "mushroomy" smell would also indicate a fungal infection.  Those are not treatable, unfortunately.

02/08/2014 at 15:00

 This is what it looks like under the bark. There is no mushroomy smell and no signs of oozing. A screwdriver only goes in about 5mm.


02/08/2014 at 15:29

Hi Magnum

A Reddy Brown discolouration on the trunk is Fire Blight

02/08/2014 at 18:58

I think Buddyboy is right.

20/09/2014 at 10:01

I have a similar problem and from the thread I think that my tree has Leaf Spot.  I have been unable to find any information relating to the treatment (if there is one) .  Any information would be appreciated.

20/09/2014 at 10:25


 If you are positive it is only Leaf spot, it can be either Fungal or bacterial, to combat this all leaf litter needs to be lifted and disposed of now and after leaf fall to limit the infection, if feasible you can spray with....Bayer sythstane fungal fighter

14/10/2014 at 12:33

Ive got 2 trees one garden centre bought another from wild stock the one from wild stock has grown the bigger but both have always had good foliage and berries to feed the local birds the wild one this rear is bare of folage and berries the other is still looking lovely covered in leaf and berry the wild one my favoured one looks so sad and the branches are looking deformed with big knobbly growths any idea whats wrong with it

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