What's eating my siberian iris?

Siberian Iris (Iris sibirica) is one of the toughest irises but still faces iris borers, aphids, and thrips. Iris borer caterpillars are the most destructive pest, tunneling down leaf blades into rhizomes. Slugs occasionally damage foliage. Deer generally avoid this plant but rabbits may nibble young shoots.

Ragged notching on leaf margins in spring, followed by water-soaked streaks; caterpillars tunnel down into the rhizome causing rot and plant collapse Remove and destroy egg-laden old foliage in autumn; squish larvae in leaves in early spring; apply beneficial nematodes to soil; cut out and discard infested rhizomes

Soft colonies on leaf bases and flower stalks; honeydew and sooty mold; flowers may be distorted Spray with insecticidal soap or a strong water blast; encourage natural predators like ladybirds

Silvery stippling and streaking on petals and foliage; flowers look scorched or fail to open fully Remove heavily infested flowers; apply spinosad spray at bloom time if damage is severe