Diagnosing Problems on Tibouchina (Glory Tree): Lichen, Root Rot, and Borers

Your Tibouchina’s greenish-gray crusty bark patches are lichen—a harmless symbiotic organism that often appears on mature trees. It can be peeled off if desired but does not harm the tree.

Branch Dieback Causes

• Wet soil and mushroom root rot: Excessive moisture can lead to root rot. Treat soil with a fungicide like Daconil and improve drainage if possible.
• Borers: Look for small holes in branches. If present, spray with Ferti-Lome Borer, Bagworm, Tent Caterpillar Spray multiple times.

Action Plan

Check soil moisture and drainage. If soil stays soggy, address drainage and apply a soil drench fungicide. Inspect branches for borer holes and treat accordingly. The tree may recover if the primary stress is relieved.