Ants in Hollow Cherry Tree: Decay Management and Cosmetic Fill

A healthy-looking cherry tree has hollow trunks with ants. Owner wants to eliminate ants, fill hollows, and save the tree. Someone suggested cement—bad idea.

Hollow Tree Reality

Decay fungi enter through bark wounds, hollowing dead heartwood. The living cambium (under bark) is unaffected. Hollow trees can live decades if the outer cylinder is sound.

Ant Management

• Spray insecticide into hollow (any ant killer)
• Place ant baits around base
• Ants don't cause decay—they exploit it

Filling Hollows: Cosmetic Only

• NO CEMENT—rigid, damages flexing tree, traps moisture
• Expanding foam (spray insulation)—flexible, cosmetic only
• Don't overfill—stop at bark line

Filling does not stop decay or strengthen the tree.

Real Tree Care

Fertilize with 10-10-10 at 1 lb/inch trunk diameter annually. Maintain vigor to maximize sound wood production. Monitor for structural weakness (large dead limbs, cracks). Consult ISA-certified arborist for risk assessment if near targets.