Old Willow Borers: Insecticide + Fertilizer for Recovery

4-Foot Diameter Willow with Borers and Thin Foliage

Large old willow shows bark peeling, worms under bark (borers), and spring growth only at branch tips. Safety concern: huge limbs.

Borers: Trunk/branch spray with borer-labeled insecticide (permethrin, bifenthrin). Garden center can recommend.
Fertilize: Balanced fertilizer (10-10-10) at dripline, water in. See NDSU guide: ext.nodak.edu/extpubs/plantsci/trees/h1035w.htm
Safety: Certified arborist MUST assess structural risk. Large limbs over targets = liability.

Borers + age + possible root issues = tree conserving energy. Fertilizer + borer control may restore vigor.

Trees: Weeping Willow with Bark Loss and Deformity: Internal Decay, Removal Advised; Red Spikes on Willow Trunk? It’s Borer Frass—Here’s What to Do; Weeping Willow Borer Damage: Treatment and Prevention; Maple Tree Limb Crack with Larvae: Remove Limb, Treat Borers; Curly Willow Sucker Management: Why Wrapping Fails and Pruning Works; Pecan Webworms: Trunk Treatment for Tall Trees; Saving an Elm Tree from Borer Infestation; Borers in Young Maple; Lilac Decline; Willow Pruning Bleeding: Normal, No Seal Needed; Weeping Willow Sucker Removal and Fertilization Guide

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