Troubleshooting
Lamance Iris problems — and how to fix them
Lamance Iris (Iris brevicaulis) is generally low-drama, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Iris borer (Macronoctua onusta)
Larvae tunnel into rhizomes in spring, providing entry points for bacterial soft rot; remove and destroy infected rhizomes, treat with a systemic insecticide in early spring when larvae are young.
Bacterial soft rot (Pectobacterium carotovorum)
Causes foul-smelling, mushy rhizomes, often following borer damage or waterlogging; cut out affected tissue, dust with sulphur fungicide, and improve drainage to prevent recurrence.
Prevent lamance iris problems before they start
Most lamance iris issues are care-mismatch, not bad luck. Dial in the basics:
Lamance Iris problems — FAQ
Why is my lamance iris iris borer (macronoctua onusta)?
Larvae tunnel into rhizomes in spring, providing entry points for bacterial soft rot; remove and destroy infected rhizomes, treat with a systemic insecticide in early spring when larvae are young.
Why is my lamance iris bacterial soft rot (pectobacterium carotovorum)?
Causes foul-smelling, mushy rhizomes, often following borer damage or waterlogging; cut out affected tissue, dust with sulphur fungicide, and improve drainage to prevent recurrence.