Troubleshooting
Iris problems — and how to fix them
Iris (Iris germanica) 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.
No flowers
Too deep, too much shade, or overcrowded — divide.
Soft rotting rhizomes
Iris borer or wet rot; dig and discard, replant in dry sunny spot.
Leaf spot
Fungal; cut back foliage to 15 cm in late autumn.
Stem topples in wind
Stake tall varieties.
Faded clumps after years
Divide every 3-4 years in midsummer.
Prevent iris problems before they start
Most iris issues are care-mismatch, not bad luck. Dial in the basics:
Iris problems — FAQ
Why is my iris no flowers?
Too deep, too much shade, or overcrowded — divide.
Why is my iris soft rotting rhizomes?
Iris borer or wet rot; dig and discard, replant in dry sunny spot.
Why is my iris leaf spot?
Fungal; cut back foliage to 15 cm in late autumn.
Why is my iris stem topples in wind?
Stake tall varieties.
Why is my iris faded clumps after years?
Divide every 3-4 years in midsummer.