Lichen on Orange Tree: Symptom, Not Cause

Light green growth (likely lichen) on orange tree. Owner fears it's killing the tree.

Lichen Is Harmless

Lichens use bark for support only—they don't parasitize. Their presence indicates stress (poor vigor, thin canopy) but doesn't cause it.

A healthy, vigorous canopy will naturally suppress lichen.

Trees: Black Walnut Fern-Like Growth: Harmless Lichens, Not a Disease; Ash/Hickory Leaf Spot: Fungal Disease Management and Tree Identification; Lichens on Trees: Harmless Indicators of Stress, Not Disease; Sawdust Threads on Oak Tree: Wood Borers or Caterpillar Frass—Diagnosis Steps; Lichens on Weeping Cherry: Harmless Indicators of Thin Canopy; Lichens on Trees: Harmless Epiphytes or Hidden Threat?; Gray Fungus on Large Trees: Lichens, Not a Disease; Killing a Nuisance Tree Near Pool: Cut It Down, Don't Just Poison It; Decay Fungi vs. Oak Wilt in Tennessee Oaks; Lichens on Transplanted Live Oaks: Cosmetic Concern, Not a Threat

Garden Articles

Plants