What's eating my polystichum aculeatum?

Polystichum aculeatum (hard shield fern) is a tough evergreen garden fern. Slugs and snails are the chief pest, attacking tender spring croziers before the tough leathery fronds harden. Vine weevil can devastate container-grown plants. Once established in the ground, this fern is largely resistant to insect damage and ignored by deer.

Scalloped, chewed edges on young fronds; mucus trails on fronds and soil in spring. Apply ferric phosphate pellets around the crown in early spring; use copper barriers for pot plants; hand-remove at night.

Adult feeding creates notched frond margins; white C-shaped grubs destroy roots causing collapse. Drench soil with Steinernema kraussei nematodes in spring and autumn; check root ball when repotting and remove grubs manually.

Soft insects clustering on new frond bases and stems; honeydew attracts ants. Remove with a water jet or insecticidal soap spray; natural predators typically keep outdoor populations in check.