What's eating my polypodium cambricum?

Polypodium cambricum (Welsh polypody) is a resilient, largely trouble-free garden fern. Slugs and snails occasionally target new fronds in autumn, when this fern is actively growing. Vine weevil is the main risk for container-grown plants. Its leathery texture and alkaline-soil preference make it less attractive to most pests than many other ferns.

Ragged holes in new fronds, which emerge in late summer and autumn unlike most ferns; damage is typically superficial on mature leathery fronds Apply iron phosphate pellets or slug nematodes in autumn when fronds emerge; clear away dead leaves and debris where slugs shelter; sharp grit mulch around the rhizomes helps deter them

Adult beetles notch frond edges; larvae destroy roots in container plants over winter, causing frond collapse Apply Steinernema kraussei nematodes in late summer to containers; inspect and replace compost annually; imidacloprid drench as a last resort for severe grub infestations