How to Prune button fern?
Remove old leaves as they die down for the winter

button fern · Pellaea rotundifolia
Also known as: New Zealand cliff brake; round-leaved fern; tarawera
Requires a moderately fertile, ericaceous, moist but well-drained soil in full sun with protection from hot midday sun, or partial shade. In frost prone areas protect the crown with a dry winter mulch
Remove old leaves as they die down for the winter