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Large Maple with Trunk Cavity and Mushrooms: Decay Fungus, Not Emergency

Assessing a Mature Maple with a Hollow Trunk

One of two large maples died; the other has a 6-inch hole near the base with visible pulp and mushroom growths inside. The elderly owners can't afford removal and fear it will fall on the house.

Expert Reassurance

Decay fungus entered a bark wound and is rotting the dead heartwood—living tissue is just under the bark.
Mushrooms are the fungus fruiting; they don't kill the tree.
If the canopy is full and green, the tree is structurally sound for many years.
Fertilize with 10-10-10 at 1 lb per inch trunk diameter to boost vigor.

No need for drain tubes or wound fillers. Monitor for increasing lean or canopy dieback.

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