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Walnut Trunk Grubs: Borer Infestation, Treat and Fertilize

Grub
Bark/Tree Damage

Mature walnut has 24″ diameter area with white grubs (borers) and elder bugs. Spray bark with Merit or Onyx. Borers indicate stress; fertilize with 10‑10‑10 at 1 lb per inch trunk diameter now and in spring.

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