What's eating my osmunda regalis 'purpurascens'?

Royal fern 'Purpurascens' is a large, moisture-loving garden fern. Slugs and caterpillars can damage fronds, while aphids may colonize new growth. Osmunda ferns are notably deer-resistant. Vine weevil is rarely a problem given their preference for open ground near water. Rust fungi occasionally affect fronds in humid conditions.

Holes and tattered fronds on young growth, especially in spring along pond margins and boggy spots Ferric phosphate pellets; clear debris; encourage natural predators like hedgehogs and ground beetles

Sections of frond eaten from the margin; feeding may be by moth or sawfly larvae Hand-pick; use Bacillus thuringiensis (Bt) spray for moth caterpillars; inspect frond undersides regularly

Soft new growth distorted; honeydew deposits encourage sooty mold on frond surfaces Knock off with a strong water jet; insecticidal soap spray; encourage predatory insects