What's eating my geum rivale 'leonard's variety'?

Geum rivale 'Leonard's Variety', the native water avens type, faces the same trio of geum sawfly, aphids, and slugs as its cultivated relatives. Sawfly larvae are the single worst threat. Growing in moist, part-shaded conditions can increase slug pressure. The plant tolerates moderate defoliation and regrows reliably.

Larvae feed on wild and cultivated Geum species alike, skeletonising leaves from late May; extensive defoliation is possible in heavy infestations. Monitor from late May; hand-pick larvae. Mulch surface lightly in autumn then disturb in spring to expose overwintering cocoons to birds. Nematode soil drench offers additional control.

Green aphid colonies cluster on shoot tips, weakening growth and excreting honeydew. Dislodge with water; use insecticidal soap if needed. Ladybirds, hoverflies and parasitic wasps provide good natural control when habitat is available.

Holes in leaf blades and severed young stems; damage worst in cool, damp spring conditions typical of this plant's preferred habitat. Ferric phosphate pellets are safe around wildlife. Copper rings or sharp grit around crowns deter slugs. Reduce by hand-picking after dark.