Leyland Cypress Browning: Seiridium or Botryosphaeria Canker

Inner needle browning is normal, but outer branch dieback on Leyland cypress signals Seiridium canker or Botryosphaeria (Bot) canker—two serious fungal diseases.

Differentiation

See detailed comparison and control at: UGA Extension

General Management

• Prune out dead branches well below cankers. Sterilize tools.
• Improve drainage, avoid overhead irrigation.
• Fungicides limited; focus on cultural health.