What's eating my copper iris?

Copper Iris (Iris fulva) faces the iris borer as its most destructive pest — larvae tunnel into rhizomes and invite bacterial rot. Aphids cluster on leaves and buds in spring, while slugs and snails target flowers. As a Louisiana swamp iris, it is less prone to borer damage than bearded irises grown in dry soil.

Pinkish larvae hatch in spring and tunnel from leaf tips down into the rhizome; infested plants show ragged leaf notches, soft rotting rhizomes, and a foul smell. Clear dead foliage in autumn to destroy overwintering eggs; crush young larvae visible in leaves in early spring; dig and discard rotted rhizome sections.

Green or grey colonies on new growth and buds; sap feeding causes leaf distortion and poor flowering. Crush by hand or spray with insecticidal soap; a strong water jet removes light infestations; avoid broad-spectrum insecticides that kill beneficial insects.

Ragged holes eaten in flower petals and tender new growth, particularly in the moist conditions this species prefers. Handpick at dusk; iron phosphate bait pellets are effective and safe around water and wildlife.

Tiny insects cause silver streaking and distortion on leaves and petals; damage is most visible on flowers. Remove and destroy affected flowers; apply neem oil or insecticidal soap to foliage; avoid overhead watering that spreads thrips.