What's eating my dryopteris filix-mas 'linearis polydactyla'?

Dryopteris filix-mas 'Linearis Polydactyla' is a hardy garden fern with few serious pest problems. Slugs may nibble young unfurling fronds in spring, and vine weevil grubs can attack roots in containers. Caterpillars occasionally chew frond edges. The plant's leathery fronds generally deter most feeders, making it one of the easier ferns to grow pest-free.

Irregular holes and ragged edges on newly emerging fronds (croziers) in spring; mature fronds are largely left alone Apply iron phosphate slug pellets around the plant; use beer traps or sharp grit mulch as barriers; go out at night to hand-pick slugs; apply Phasmarhabditis nematodes when soil is above 5°C

Adults notch frond margins in summer; larvae eat roots over autumn and winter, causing sudden wilting and plant collapse — worst in containers Apply Steinernema or Heterorhabditis nematodes in August–September when soil is 12–20°C; use imidacloprid drench for severe infestations; check root balls of container plants regularly

Holes or chewed sections in frond pinnae; moth larvae are the typical culprit in summer Hand-pick caterpillars and egg masses; encourage birds to feed nearby; spray Bacillus thuringiensis (Bt) for large infestations