Troubleshooting
Wart Fern problems — and how to fix them
Wart Fern (Microsorum scolopendria) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Brown, crispy frond edges
Almost always low humidity or dry, mineral-laden water; raise ambient moisture and switch to rainwater or filtered water.
Rhizome rot
Caused by burying the surface rhizome or keeping the mix soggy; let the rhizome sit on top and use an open, draining medium.
Scale and mealybugs
Sap-suckers hide along the rhizome and frond undersides among the sori; wipe off and treat with horticultural soap, checking new growth weekly.
Sori mistaken for pests
The neat warty rows of brown spore cases on the underside are reproductive sori, not insects or disease, and need no treatment.
Prevent wart fern problems before they start
Most wart fern issues are care-mismatch, not bad luck. Dial in the basics:
Looking for wart fern in general rather than its problems? Read the full wart fern care guide — light, water, soil and feeding.
Wart Fern problems — FAQ
Why is my wart fern brown, crispy frond edges?
Almost always low humidity or dry, mineral-laden water; raise ambient moisture and switch to rainwater or filtered water.
Why is my wart fern rhizome rot?
Caused by burying the surface rhizome or keeping the mix soggy; let the rhizome sit on top and use an open, draining medium.
Why is my wart fern scale and mealybugs?
Sap-suckers hide along the rhizome and frond undersides among the sori; wipe off and treat with horticultural soap, checking new growth weekly.
Why is my wart fern sori mistaken for pests?
The neat warty rows of brown spore cases on the underside are reproductive sori, not insects or disease, and need no treatment.