Fungi on Horse Chestnut

Chestnut1976 · #1 (**permalink**) 12-01-2009, 08:57 PM

Hi there,

This is my first post and I am a complete novice when it comes to fungi. I have been concerned about the condition of the horse chestnut in my garden for some time and it has been suggested that it is suffering from bleeding canker from the bark and leaf miner. The bark is a poor condition and the leaves wither prematurely each season.

I found these whopping fungi on the tree two weeks ago - it was actually lighter in colour at the start (more like a standard mushroom grey/white) and has deteriorated to this darker brown colour.

Any ideas on what kind of fungi this is? It is actually growing from a stump on the tree where a branch once was prior to being pruned many years ago.

Many thanks for your input....

ron1863 · #2 (**permalink**) 12-01-2009, 09:06 PM

Hi and a warm welcome to WAB Chestnut. It looks like an Oyster mushroom - Pleurotus ostreatus. One of out experts will put you right though.

Ron

Lancashire Lad · #3 (**permalink**) 12-01-2009, 09:08 PM

This looks like Pleurotus ostreatus (Oyster Fungus), that past it's best.

Regards
Mike.

Chestnut1976 · #4 (**permalink**) 12-01-2009, 09:24 PM

Thanks for the link Mike, thats exactly it. Is this a bad sign that the tree could be dying?

Lancashire Lad · #5 (**permalink**) 12-01-2009, 09:31 PM

Quote:

Originally Posted by Chestnut1976

Thanks for the link Mike, thats exactly it. Is this a bad sign that the tree could be dying?

I'm by no means qualified to advise you of the potential consequences for the tree, but would say that it can't be anything other than a bad sign really.
I've only seen such fungi on damaged or dead/decaying trees

I'm sure someone with more knowledge will give a better diagnosis.

Regards
Mike.

NickCantle · #6 (**permalink**) 12-01-2009, 09:37 PM

I think that means bad news for your tree. Pluerotus ostreatus is a saprotroph, therefore rendering your tree a victim of slow decay and death.

...

I think

mollisia · #7 (**permalink**) 12-01-2009, 10:02 PM

Hallo,

if it were a saprotroph, then it wouldn't harm. But Nick surely meant "parasitic" and indeed Pleurotus species are (also) week parasites. Especially Pleurotus ostreatus usually attacks Fagus at the places were big branches broke of or where a flash damaged the stem. But Pleurotus also can grow saprobiotic, otherwise there would be no chance to bread it on straw.

For your tree this means that it is attacked, yes, but by a fungus which is only weekly parasitic. If it would be a sound tree except for this place of fungal attacking, there would be no problem for the next decades. But as your tree is weekend (this word exists? Looks like having weekend *gg*) already, may be the attack of Pleurotus gives him another hit that either may give it the rest or makes it vulnerable for other stronger parasitic fungi, e.g. Laetiporus or Armillaria.

If your house is in danger of the possibly felling tree one day, then it would be best to contact a specialis for these trees who can analize how dead or alive your tree still is.

best regards,
Andreas

NickCantle · #8 (**permalink**) 12-01-2009, 10:11 PM

So does that mean that the tree was already decaying and/or dying from an attack from another fungus? Once the tree is already on its way to death, P. ostreatus feeds off of the already decaying matter?

I did read somewhere that P. ostreatus is a saprotroph though

Morchella · #9 (**permalink**) 12-01-2009, 10:19 PM

Hi there,

The most serious threat to your tree is almost certainly the bleeding canker. Interestingly this was originally though to be due to a fungus, Phytopthora, but has now been found to be caused by bacteria.

Unfortunately there's no treatment for the canker (there is for leaf miner but that's the lesser of the tree's problems) although some trees do recover. The danger point for your tree will be if the canker spreads so that it encircles the trunk as this will almost certainly kill it.

I would have it checked out by an arboriculturist if you are concerned that it might be unstable. Although I'd be tempted to keep it there until after next year's crop of Pleurotus!

Laura

Chestnut1976 · #10 (**permalink**) 12-01-2009, 10:44 PM

Thanks for the responses, I just remember that I took a few shots of the fungi on my mobile two weeks ago when it was fresh and they do look like the Oyster fungi everyone has mentioned.

Molissa - How can a tree surgeon tell how alive or dead the tree is? It does look sick with missing and girdled bark, but how can they tell if it is dying or may recover?

Morchella - You sound you have experience with the Horse Chestnuts trees, is this a problem you have encountered first hand? I would be interested to hear of the treatment for the leaf miner and understand what a arboriculturist does to establish if the tree is stable or not...