Tricolor Beech Decline: Borers, Not Sun, in Northwest Indiana

Joe's 6-ft tricolor beech (planted autumn) shows brown curling leaves on one section and scattered leaf holes. Planted 30 ft from mature maple (east) and black walnut + pines (west). NW Indiana location.

Diagnosis: Borer Infestation

Sun unlikely cause—shade pattern described protects tree. Borers target stressed trees; symptoms include:

• Branch-specific dieback
• Sap weeping
• Bark stripping/sloughing
• Clear-wing moth or beetle adults

Treatment

1. Spinosad spray: Organic, effective on borer larvae, safe for beneficials. Apply to trunk and affected branches.
2. Prune dead/dying branches: Cut back to healthy wood.
3. Remove loose bark: Eliminates borer hiding spots.

Transplanting?

No—fibrous roots = high transplant shock risk in growing season. Wait until winter dormancy if relocation ever needed. Improve drainage with grading instead.

Walnut Note

Juglone from black walnut can affect sensitive plants, but beech is tolerant. Distance (30 ft) + buffer trees = minimal risk.