What's eating my geranium psilostemon?

Geranium psilostemon (Armenian cranesbill) is a tall, vigorous border plant that suffers few serious pest attacks. Vine weevil grubs can damage crowns, capsid bugs cause leaf tattering in early summer, and slugs target new spring growth. Its large, bold foliage usually outpaces minor feeding damage. Deer may occasionally browse in exposed gardens.

Soil-dwelling larvae eat roots and crown tissue, weakening or killing the plant; most damaging in containers. Adults leave notched leaf margins after night-time feeding. Apply nematodes (Steinernema kraussei) to moist soil in late summer. Grow in open ground where possible; border conditions are less favourable to vine weevil than containers.

Tiny holes and shredded appearance in young leaves from May into July; shoot tips may be distorted or blind as toxins prevent normal cell growth. Spray with pyrethrin or deltamethrin in the evening. Clear weedy vegetation around plants where capsids overwinter as eggs. Damage is usually cosmetic on vigorous plants.

Ragged holes in emerging spring foliage near the crown; slime trails visible at ground level. G. psilostemon grows vigorously enough to outgrow most slug damage. Apply ferric phosphate pellets in spring when shoots emerge. Night-time hand-picking is effective. Established plants need minimal intervention.