Pest identification
What's eating my triangle fern?
Spider mites
Signs: Pale stippling and fine webbing on frond undersides; fronds dry and bronze in low humidity
Control: Raise humidity; spray with insecticidal soap or neem oil every 5–7 days; rinse undersides with water
Aphids
Signs: Soft, clustered insects on new fronds and growing tips; distorted fronds and sticky honeydew
Control: Blast off with a strong water jet; apply insecticidal soap spray; repeat every 3–5 days if needed
Scale insects
Signs: Waxy brown bumps along frond stems; yellowing and weakened fronds
Control: Remove manually with an alcohol-soaked cotton swab; apply neem oil spray every 10 days
Keep triangle fern pest-free
Healthy plants resist pests best. Get the basics right:
Triangle Fern pests — FAQ
What is eating my triangle fern?
Triangle Fern (Pteridium aquilinum) grown indoors is susceptible to spider mites and aphids, particularly in warm rooms with low humidity. Scale insects and mealybugs can also colonise the coarse fronds. Note: this species spreads aggressively outdoors — keep it containerised indoors and do not plant it in open garden soil.
How do I get rid of spider mites on triangle fern?
Pale stippling and fine webbing on frond undersides; fronds dry and bronze in low humidity Raise humidity; spray with insecticidal soap or neem oil every 5–7 days; rinse undersides with water
How do I get rid of aphids on triangle fern?
Soft, clustered insects on new fronds and growing tips; distorted fronds and sticky honeydew Blast off with a strong water jet; apply insecticidal soap spray; repeat every 3–5 days if needed
How do I get rid of scale insects on triangle fern?
Waxy brown bumps along frond stems; yellowing and weakened fronds Remove manually with an alcohol-soaked cotton swab; apply neem oil spray every 10 days