What's eating my zigzag iris?

Zigzag Iris is attacked by the iris borer moth caterpillar, which tunnels into rhizomes causing rot — this is by far the most destructive threat. Aphids cluster on new growth in spring, while slugs and snails rasp leaves and flower buds at ground level. Remove dead foliage in autumn to destroy overwintering borer eggs.

Pink caterpillars tunnel down leaf blades into rhizomes, leaving water-soaked streaks and eventual soft rot; infested rhizomes smell foul and collapse Remove and destroy all foliage in autumn to eliminate eggs. Crush larvae found inside leaves in spring. Apply spinosad at egg hatch, or drench soil with beneficial nematodes (Heterorhabditis bacteriophora) in late summer to kill larvae in rhizomes

Soft-bodied colonies on young shoots and flower buds; sticky honeydew residue, distorted growth, reduced vigour Blast off with a firm jet of water; repeat applications of insecticidal soap; encourage ladybirds and lacewings as natural predators

Irregular holes and ragged edges in leaves and petals, especially at ground level; silvery slime trails overnight Apply iron phosphate pellets around plants; set out beer traps; hand-pick at dusk; keep mulch away from crown to reduce hiding spots

Fine silver-white streaking and stippling on petals and leaves; flowers distorted or fail to open properly Remove and dispose of damaged blooms. Spray with insecticidal soap or spinosad. Avoid excess nitrogen that promotes the soft growth thrips prefer