Deciduous Dendrobium Leaf Drop and Scale Insect Treatment

Leaf loss in dendrobiums around Easter is often natural for deciduous types. However, "seed-like" bumps on leaves indicate scale insects or aphids—common pests requiring prompt action.

Natural vs. Problematic Leaf Drop

Deciduous dendrobiums (e.g., nobile types) shed leaves annually after flowering. This is normal. The plant enters a dry rest period. Watering during this phase causes root rot—the #1 killer of these orchids.

Pest Identification and Eradication

• Scale/aphids: Tiny, immobile bumps on leaves/stems. Often mistaken for seeds.
• Treatment: Swab with isopropyl alcohol on a Q-tip. Follow with insecticidal spray per label.
• Persistence: Repeat weekly until no new pests appear; eggs hatch over time.

Repotting After Bloom

1. Stop watering during rest period.
2. After flowering, unpot and inspect roots.
3. Remove mushy/rotten roots.
4. Repot in fresh orchid mix (bark-based).

Key Takeaways

• Leaf drop in spring = likely natural for deciduous dendrobiums.
• "Seeds" on leaves = scale/aphids—treat with alcohol + spray.
• Keep dry during rest; repot post-bloom.

Distinguish natural cycles from pests to avoid overwatering a resting plant.