Fungus on oak tree

[Glen]

This is my oak. As you can see there is something on its root that should not be there! Is it terminal? What is the prognosis please?

steephill

Looks like Beefsteak Fungus - Fistulina hepatica. It is a parasitic fungus common on oak and found low down as your example. It causes brown rot in the trunk which interests furniture makers as it produces richer coloured, darker wood. You might spot it "bleeding" like the one below which helps explain the beefsteak name.

There is nothing you can do to treat it but it would take many decades to damage the tree to the point where you might need to think about removing it.

[Glen]

It takes decades to grow a tree! Is now the time to think about planting a replacement?

BobTheGardener

You could add a replacement nearby, but I wouldn't consider removing a tree of that age!  Ancient oaks very often have the whole of the heartwood rotted away, but still survive, and the rotting wood supports many, many forms of wildlife.  As steephill says, it'll probably be 20 or 30 years before it does any harm.

[Glen]

Humn. 20 years is not very long to grow a new tree to take over the role of this one.

The pictured root is actually touching a road where occasionally a clumsy driver will injure the tree, so the oak is not in a location where it can be left to slowly fall.

Maybe I should have one transplanted. As the roots will be all over the place, how close can a new one be placed please?

steephill

When I said many decades I meant probably not in your lifetime so I wouldn't worry about it. For peace of mind you could get an arborist to inspect the tree but that won't be a cheap option.

Skandi

It's hard to get a sense of scale on your picture, but that oak is at least 300 hundred up to 500 years old, The fungus won't do it much harm in our lifetimes. as bob says even being hollow is not a death sentence for such a tree

pansyface

And you can get your revenge by eating the fungus. Although if it’s near a roadside, maybe not. 😬