Iris germanica · Perennial
Iris leaf spot: Remove and dispose of all leaf debris at the end of the year and pick off lightly infected leaves during the season.
Bacterial soft rot: Ensure well-drained soil and partially exposed rhizomes; cut away affected tissue with a disinfected knife and allow to dry before replanting.
Slugs and snails: Use physical barriers like copper tape or eggshells, and hand-pick pests at night; avoid chemical slug pellets where possible.
Iris rust: Improve air circulation around plants and remove infected foliage to slow the spread of spores.
Aphids: Encourage natural predators like ladybirds and lacewings, or blast off infestations with a strong jet of water.