Black Leaf Tips and Spots on Cymbidiums: Salt Buildup, Sunburn, or Disease?

Decoding Black Discoloration on Cymbidium Leaves

Black leaf tips on Cymbidiums typically signal excess salt accumulation in the potting media. Sources include over-fertilizing, mineral-heavy water, or decomposed media that concentrates salts. These salts damage roots and cause tip dieback.

Other Causes of Black Spots

• Base of leaf: Often fungal, caused by water sitting in leaf axils overnight.
• Mid-leaf spots: Could be sunburn from intense light/heat, or bacterial infection if spots enlarge.

Treatment Plan

1. Flush the pot thoroughly with pure water to leach salts.
2. Repot in fresh media if the mix is broken down.
3. Remove affected tissue: Cut well below blackened areas with a sterile tool (single-edge razor blades work well). Sterilize between cuts.
4. Adjust care: Fertilize weakly, weekly. Water in the morning so foliage dries by night. Provide bright light but shield from harsh midday sun.

Monitor new growth—clean, green leaves indicate recovery. If black spots spread rapidly, suspect bacterial infection and consider a copper-based bactericide.