What's eating my geranium sylvaticum?

Geranium sylvaticum (wood cranesbill) is a hardy garden perennial with notably few serious pest problems. Vine weevil, slugs, and aphids occasionally cause damage, and rabbits will browse young growth. It is generally considered a robust, low-maintenance plant that most common garden pests tend to leave alone.

Larvae eat roots, causing sudden wilting and plant death, especially in containers; adults leave ragged notches around leaf margins. Apply nematodes (Steinernema kraussei) to moist soil in late summer; hand-pick adult beetles at night by torchlight.

Irregular holes in young leaves and stems, especially in spring; slime trails visible on foliage and surrounding soil. Apply iron phosphate pellets around plants; go out at night to hand-pick; use copper tape on containers.

Clean, close-cut grazing of young stems and leaves at the base; most damaging in spring on freshly emerging growth. Surround beds with wire mesh fencing (at least 90 cm tall, buried 30 cm); use rabbit deterrent sprays around the planting area.