What's eating my valerian?

Valerian attracts cats, which can dig up and roll on roots — a surprisingly serious threat. Aphids colonise tender shoot tips, and slugs damage young plants in spring. Cats are drawn by the same valerenic-acid scent that makes the root medicinally attractive. Wire-mesh cloches around new plantings deter cats and slugs alike.

Crushed stems and crowns, disturbed soil, uprooted roots — cats roll on and bite the plant in response to valerenic acid, especially in spring. Place wire-mesh or plastic-bottle cloches over crowns; use prickle strips or citrus-peel deterrents on surrounding soil.

Sticky, curled growing tips; green or black aphid clusters on stems; honeydew invites sooty mould. Spray with insecticidal soap or neem oil solution; introduce or encourage natural predators such as ladybirds and hoverflies.

Shredded young leaves and gnawed stems at soil level in spring; silvery slime trails visible in the morning. Apply iron-phosphate slug pellets or set beer traps; clear mulch away from the crown to reduce hiding spots.