Mushrooms on Ash Trunk: Internal Decay, Not a Death Sentence

Oyster-like mushrooms growing from a bark depression on your 25-foot Gulf Coast ash indicate internal wood-decay fungi. The conks (mushrooms) are merely the fruiting bodies; the fungus has been digesting dead heartwood for years.

What This Means

• Decay fungi enter through wounds and consume only non-living central wood.
• They do not attack living sapwood or cambium—tree health isn't directly threatened.
• Structural weakness develops slowly over decades; large limbs may eventually hollow and break.

Management

No treatment eliminates established trunk fungi. Instead, boost vitality: broadcast 10-10-10 fertilizer at 1 lb per inch of trunk diameter before a rainstorm. A vigorous tree compartments decay and adds sound new wood annually. Monitor for major limb failure; otherwise, the ash can thrive for many more years.