Mushrooms that kill trees????

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teamtree

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I am not saying I am the most knowledgable but I heard something tonight that kind of blew my mind. I was in a neighboring town checking things out and I stop by one of the bars to grab a bite to eat. The local mushroom experts (per the bartender) was talking about all the mushrooms around. He then started to tell another patron that mushrooms (honey mushroom) will kill the trees. I simply asked him to clarify and explain. He said the fingers of the mushrooms will go up into the tree and kill it.

I understand fungal diseases and I understand fruiting bodies.....but can anyone provide more information or insight to what he may have been talking about.
 
He is not too far off... Honey mushrooms are Armillaria - which is also called shoestring root rot. http://www.na.fs.fed.us/spfo/pubs/fidls/armillaria/armillaria.htm]Read more here[/url]

It is very rare that Armillaria will kill healthy trees, but can be extremely aggressive in stressed trees. For example, look any DED-killed elm, and it was probably technically Armillaria that killed it (you can find the mycelium under the bark at the base). DED just weakened the tree enough that Armillaria could move in. that one is a 'technicallity' as DED would have killed it anyhow. Just about anytime you hear about a "Decline complex" Armillaria is involved.

Reaching in with fingers....no, and he has it a little backwards. The mycelial mat is the main part of the fungus that is growing under the tree. The honey mushrooms are what come out as fruiting bodies. But those mushrooms are all that he cares about, so he sees it backwards.
 
He is not too far off... Honey mushrooms are Armillaria - which is also called shoestring root rot. http://www.na.fs.fed.us/spfo/pubs/fidls/armillaria/armillaria.htm]Read more here[/url]

It is very rare that Armillaria will kill healthy trees, but can be extremely aggressive in stressed trees. For example, look any DED-killed elm, and it was probably technically Armillaria that killed it (you can find the mycelium under the bark at the base). DED just weakened the tree enough that Armillaria could move in. that one is a 'technicallity' as DED would have killed it anyhow. Just about anytime you hear about a "Decline complex" Armillaria is involved.

Reaching in with fingers....no, and he has it a little backwards. The mycelial mat is the main part of the fungus that is growing under the tree. The honey mushrooms are what come out as fruiting bodies. But those mushrooms are all that he cares about, so he sees it backwards.

It doesn't take much to stress the trees though. Summer drought stress and then overwatering can do it. We find armillaria affects Arborvitae hedges as well as many of our conifers ie western hemlock and douglas fir.
 
Mycelia move in the tree too, not just the ground. Armillaria is treatable:
This pest should be managed with IPM treatments aimed at compartmentalization.”
I flipped through pages 354–367 of my book on
diseases. “‘Remove soil from stem tissue, dry the area,
deeply aerate nearby soil, clean and heat the lesions, and
amend the soil with calcium fertilizer and beneficial
microorganisms to help speed compartmentalization.’”
 
Friend of mine took me to see his FIL and look at his trees...they were all topped a while ago and now dying back and he didn't know why. Said he got them topped so the tops wouldn't rot off and fall down, I was like o_O, hmmm not sure what to tell you.
 
Mycelia move in the tree too, not just the ground. Armillaria is treatable:
This pest should be managed with IPM treatments aimed at compartmentalization.”
I flipped through pages 354–367 of my book on
diseases. “‘Remove soil from stem tissue, dry the area,
deeply aerate nearby soil, clean and heat the lesions, and
amend the soil with calcium fertilizer and beneficial
microorganisms to help speed compartmentalization.’”

I've seen some research that armillaria is treatable with a high phosphate fertilizer. We see it most often in hedging cedars (arborvitae) or in large native conifers.

Hedging cedars are so stressed just by their very nature of being sheared yearly (and having a small root mass), that once one shows signs, it is beyond help.

The large natives usually have a limited opportunity to treat due to their size.
 
The large natives usually have a limited opportunity to treat due to their size.

But only a small part of them typically needs treating; the infected area, and the soil below.

i've treated a lot of 24"+ trees...
 

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