Mealybugs or scale

Sticky leaves with cottony tufts or small brown bumps point to mealybugs or scale insects feeding on the sap.

Diagnosis

Mealybugs or scale

What's happening

Mealybugs look like little tufts of cotton tucked into leaf joints, while scale appear as small, hard brown bumps clinging to stems and leaf undersides. Both pierce the plant to drink its sap and excrete a sticky honeydew that coats the leaves and can grow sooty mold. A heavy infestation drains the plant and stunts new growth.

How to fix it

Isolate the plant. Dab visible mealybugs and scale directly with a cotton swab dipped in rubbing alcohol to kill them on contact, then wash the foliage and spray the whole plant thoroughly with insecticidal soap, getting into every leaf joint and stem. Repeat the soap treatment every week for several weeks, and re-inspect often — these pests hide in crevices and rebound quickly if any are missed.

What fixes it

  • Insecticidal soap — Insecticidal soap clears mealybugs and scale on contact; reapply weekly into every leaf joint until they're gone.

If that doesn't fix it

This is general guidance based on common symptoms; individual plants vary.

Reviewed June 2026 · how we check this