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Yellow Trunk Growth on Plums, Honeysuckle, Locust: Lichens, Not Disease

10-yr flowering plums, 8' honeysuckle, older locust, rail fence: trunks turning yellow with moss-like growth. Shaded area.

Identification: Lichens

Symbiotic fungus + algae. Various colors/shapes. Not plant pathogens. Indicator of older/declining plants or shade — result, not cause. Also on rocks, power lines.

Action

None needed. Confirm via Google Images "lichens."

Expert insight provided by Steve.

Plant Diseases: Lichen Growth on Rose of Sharon: Harmless or Harmful?; Growing Clivia Without Winter Chill: Refrigerator Method for Bloom Induction; Moss-Like Growth on Trees: Epiphyte, Not Parasite; Managing Moss in a Shady, Cool-Climate Lawn; Drooping Blooms and Sick Violets: Soil Contamination Suspected; Portulaca (Moss Rose) Getting Leggy: Causes and Fixes; Hydrangea Non-Blooming Causes: Pruning Timing, Soil pH for Color, and Propagation; Managing Moss in Pavers and Organic Fertilizer Alternatives; Organic Solutions for Moss, Grubs, and Crabgrass in a Northern Westchester Lawn; Five Exceptional Ferns for British Gardens

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