Troubleshooting
Dutch Iris problems — and how to fix them
Dutch Iris (Iris hollandica) is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Bulb rot and soft rot (Erwinia/Fusarium)
The primary cause of failure, especially in heavy or wet soils. Plant in sharply drained ground; lift bulbs after dormancy if the site stays wet in summer. Store dried bulbs in a cool, dark, airy place.
Aphid-borne iris mosaic virus
Produces yellow streaking, mottling, and distortion of foliage and flowers. Manage aphid populations with insecticidal soap. Destroy infected bulbs — there is no cure. Purchase virus-indexed bulbs from reputable suppliers.
Thrips
Tiny insects rasp foliage and petals, causing silvery streaks and distorted blooms. More prevalent in warm, dry conditions. Control with insecticidal soap or spinosad; monitor plants closely during warm spells.
Prevent dutch iris problems before they start
Most dutch iris issues are care-mismatch, not bad luck. Dial in the basics:
Looking for dutch iris in general rather than its problems? Read the full dutch iris care guide — light, water, soil and feeding.
Dutch Iris problems — FAQ
Why is my dutch iris bulb rot and soft rot (erwinia/fusarium)?
The primary cause of failure, especially in heavy or wet soils. Plant in sharply drained ground; lift bulbs after dormancy if the site stays wet in summer. Store dried bulbs in a cool, dark, airy place.
Why is my dutch iris aphid-borne iris mosaic virus?
Produces yellow streaking, mottling, and distortion of foliage and flowers. Manage aphid populations with insecticidal soap. Destroy infected bulbs — there is no cure. Purchase virus-indexed bulbs from reputable suppliers.
Why is my dutch iris thrips?
Tiny insects rasp foliage and petals, causing silvery streaks and distorted blooms. More prevalent in warm, dry conditions. Control with insecticidal soap or spinosad; monitor plants closely during warm spells.