Cedar Tree Carpenter Ants: Decay Management Over Ant Control

Cedar (9 ft diameter!) with carpenter ant damage. Owner cleaned 3-inch deep decay. Asks if tree must be cut.

Ants: Secondary

Carpenter ants nest in decayed wood—they don't cause decay. Decay fungi create habitat. Ants use cracks, knots, old tunnels.

Ant Control (If Desired)

• Dust Sevin/rotenone into cavities.
• Baits (Terro) for colonies near structures.
• Spray exposed nests with bifenthrin/cyfluthrin/deltamethrin/permethrin.

Structural Reality

Hollow trees aren't automatically dangerous. Living tissue (under bark) adds wood yearly. Danger = large hollow limbs breaking. If canopy full/green, tree stable for years.

Recommendation

Don't cut. Treat ants if near house. Fertilize 10-10-10 at 1 lb/inch diameter (spring + fall) to boost vigor.