Disc Fungus on Tulip Poplar Stump: Decay Fungi Fruiting Bodies

Tan Discs on Old Tulip Poplar Stump = Fungal Conks

A tulip poplar cut 2 years ago (3-foot stump left, hollow, 5 feet wide) now has 3–4 inch tan discs on the outer bark.

What They Are

Fruiting bodies (conks) of wood-decay fungi already growing inside the hollow trunk. They produce spores to spread.

Impact

• Fungi decay only dead heartwood—the stump is already dead.
• They do not threaten nearby living trees (different host specificity).
• Over decades, decay may weaken the stump until it collapses.

Management

• No treatment needed. Fungicides don’t penetrate solid wood.
• If stump is near structures, monitor for instability.
• Fertilizing living trees nearby (10-10-10 at 1 lb/inch trunk diameter spring/fall) boosts their defense against similar fungi.

Bottom Line

This is nature recycling dead wood. No action required unless the stump becomes a safety hazard.