Fern Brown Bumps and Stickiness: Oedema or Mealybugs

Fern Brown Bumps and Stickiness: Oedema or Mealybugs

30-year-old fern with 2–3 mm brown bumps on stems/leaves (non-moving), stickiness, and fine fuzz: could be oedema (physiological, from overwatering/high humidity) or mealybugs (insects).

Oedema Management

• Reduce watering; keep slightly dry in winter.
• Lower humidity below 70%.
• Increase air circulation; space plants.
• Gradually increase light in spring.

If Mealybugs

• Spray insecticidal soap or neem oil.
• Repeat weekly until gone.

Oedema bumps are embedded; mealybugs are cottony and leave sticky honeydew. Magnification helps distinguish.