Citron Seedlings with Curling, Deformed Leaves: Spider Mites, Overfertilization, or Virus? Systematic Troubleshooting

Case History

15-month-old citron seedlings under 24/7 fluorescent lights in NJ show leaf curling, deformation, yellow flecking. Owner flushed soil, pinched leaves, sprayed insecticidal soap—no improvement. Suspects citrus chlorotic dwarf virus.

Expert Analysis

• Spider mites: Tiny, feed on leaf undersides, cause stippling/flecking. Check with magnifier at leaf-stem junctions.
• Spray injury: Yellow flecking may be phytotoxicity from soap spray.
• Overfertilization: Miracid every 2 weeks is excessive for slow winter growth.
• Virus unlikely: Symptoms don't match; seed-grown plants rarely have viruses.

Action Plan

1. Stop all sprays; monitor new growth.
2. Reduce watering; let soil dry between waterings.
3. Fertilize monthly at half strength.
4. Take a plant to a local independent nursery (not big-box) for hands-on diagnosis.

Key Insight

Indoor citrus under lights often suffers from mite buildup and fertilizer burn. Cultural correction beats chemical guesswork.