Pest identification
What's eating my spanish iris?
Iris Borer (Macronoctua onusta)
Signs: Caterpillars chew notches in leaves then tunnel into bulbs causing soft rot and plant death
Control: Clear old leaf debris in autumn to remove overwintering eggs; apply nematodes to soil; remove infested bulbs
Aphids
Signs: Colonies on stems and buds; distorted or weak flowers; honeydew attracts sooty mold
Control: Apply insecticidal soap or neem oil; blast off with water; introduce beneficial insects
Ink Disease (Mystrosporium adustum)
Signs: Black crust and rotting on bulb exterior and interior; premature yellowing of foliage
Control: Remove and destroy affected bulbs; avoid replanting irises in the same bed; ensure good soil drainage
Keep spanish iris pest-free
Healthy plants resist pests best. Get the basics right:
Spanish Iris pests — FAQ
What is eating my spanish iris?
Spanish Iris (Iris xiphium) faces iris borer in North America, aphids on flower stems, and bulb rot from fungal pathogens. Thrips can damage blooms. In the UK and Europe, ink disease is a serious bulb threat. Slugs target emerging foliage. Good drainage and autumn foliage cleanup are the main preventive measures.
How do I get rid of iris borer (macronoctua onusta) on spanish iris?
Caterpillars chew notches in leaves then tunnel into bulbs causing soft rot and plant death Clear old leaf debris in autumn to remove overwintering eggs; apply nematodes to soil; remove infested bulbs
How do I get rid of aphids on spanish iris?
Colonies on stems and buds; distorted or weak flowers; honeydew attracts sooty mold Apply insecticidal soap or neem oil; blast off with water; introduce beneficial insects
How do I get rid of ink disease (mystrosporium adustum) on spanish iris?
Black crust and rotting on bulb exterior and interior; premature yellowing of foliage Remove and destroy affected bulbs; avoid replanting irises in the same bed; ensure good soil drainage