Pest identification
What's eating my limestone oak fern?
Slugs and snails
Signs: Nibbled or holed young fronds in spring, especially in garden beds with moisture-retaining soil — unlike its natural rocky habitat
Control: Grow in sharply drained gritty or stony soil where slugs are less active; apply iron phosphate pellets; use slug nematodes in spring; sharp limestone chip mulch doubles as a deterrent and suits this plant's pH preference
Vine weevil
Signs: Adult weevils notch frond margins at night; larvae destroy the shallow rhizomes of container-grown plants through autumn and winter
Control: Apply Steinernema kraussei nematodes to containers in August–September; inspect root balls when repotting; replace old compost and treat with imidacloprid drench if larvae are found
Keep limestone oak fern pest-free
Healthy plants resist pests best. Get the basics right:
Limestone Oak Fern pests — FAQ
What is eating my limestone oak fern?
Limestone Oak Fern (Gymnocarpium robertianum) is a specialist alkaline-soil fern of rocky habitats. It is very resistant to pests. Slugs may occasionally graze tender new fronds in a garden setting. Vine weevil is a risk in containers. Its naturally rugged constitution and preference for well-drained stony ground make it one of the most trouble-free ferns to grow.
How do I get rid of slugs and snails on limestone oak fern?
Nibbled or holed young fronds in spring, especially in garden beds with moisture-retaining soil — unlike its natural rocky habitat Grow in sharply drained gritty or stony soil where slugs are less active; apply iron phosphate pellets; use slug nematodes in spring; sharp limestone chip mulch doubles as a deterrent and suits this plant's pH preference
How do I get rid of vine weevil on limestone oak fern?
Adult weevils notch frond margins at night; larvae destroy the shallow rhizomes of container-grown plants through autumn and winter Apply Steinernema kraussei nematodes to containers in August–September; inspect root balls when repotting; replace old compost and treat with imidacloprid drench if larvae are found