Spider mites
Fine webbing and a dusty, stippled look on the leaves are the signs of spider mites, the one pest that bothers an otherwise pest-proof plant.
Diagnosis
Spider mites
What's happening
Spider mites are nearly invisible sap-suckers that thrive in warm, dry indoor air. They cluster on leaf undersides, pierce the cells, and drain them, leaving a fine pale stippling that makes the deep-green blades look dull and dusty. As the colony grows they spin the telltale fine webbing in the leaf joints, and the infestation spreads quickly if left alone.
How to fix it
Isolate the plant from your others right away. Wipe both sides of every leaf with a damp cloth to knock the mites and webbing off, then spray thoroughly with neem oil, coating the undersides where they hide. Repeat every 5–7 days for three to four weeks to catch newly hatched mites, since eggs survive a single treatment. Raising the humidity around the plant afterward makes the air far less inviting for them to return.
What fixes it
- Neem oil for pests — Neem oil smothers spider mites and their eggs on contact — coat both sides of every leaf and repeat weekly.
If that doesn't fix it
This is general guidance based on common symptoms; individual plants vary.
Read the full Cast Iron Plant care guide →
Reviewed June 2026 · how we check this