Forsythia Hollow Stems and Winter Dieback: Normal Anatomy and Recovery

Forsythia's hollow stem centers (pith) are completely normal—not insect damage. The dead, leafless branches after a harsh Philadelphia winter indicate cold injury, not disease. Forsythia flower buds are less hardy than leaf buds, so blooms may fail while the plant survives.

Prune out all dead wood back to live tissue (green cambium under bark). Apply a balanced fertilizer in early spring. The plant will regrow vigorously—forsythia's natural habit is rapid, arching cane production from the base.

For better flowering next year: prune immediately after bloom (removing oldest canes at ground level), ensure full sun, and avoid late-summer fertilization that promotes tender growth vulnerable to winter kill.

The hollow stems? That's just how forsythia grows.