Saving an Old Oak from Borer Worms and Carpenter Ants

An Arkansas homeowner was told their large oak has borer worms and black ants around the base. They want to know if the tree can be saved.

Action Plan

Kill borers: Spray trunk with imidacloprid (Merit) to eliminate larvae in the wood.
Fertilize now and in fall: 10-10-10 at 1 lb per inch of trunk diameter, watered in well.
Understand ants: Carpenter ants nest in decayed wood but don't harm living tissue. They're a symptom, not a cause.

Borers target stressed trees. Fertilization improves vigor, helping the tree fight future attacks. The ants will leave once the decayed wood is gone.

Trees: Oak Borer Management: Vigor, Merit Spray, and Japanese Maple Safety; Oak Loopers Defoliating Michigan Oak: Natural Cycles, Little Control Possible; Fungus on Carved Oak Stump: Slow Decay with Bleach Treatment; Large Oak Cavity with Standing Water: Drain & Foam, Don't Cement; Assessing a Hazardous Mature Oak: When Removal Is the Only Safe Option; Saving Young Dogwoods from Borers; Evaluating Decay and Holes in an Old Oak Tree; Borers in Oak Trees: Merit and Systemic Options for Homeowners; Pine Tree with Borer Holes and Browning Tips: Likely Bark Beetles—Act Fast; Saving an Elm Tree from Borer Infestation

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