Troubleshooting
Ivan Cranesbill problems — and how to fix them
Ivan Cranesbill (Geranium 'Ivan') 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.
Geranium sawfly (Arge pagana)
Larvae skeletonise leaves in late spring and summer, leaving papery patches; hand-pick caterpillars or apply a contact insecticide; inspect the undersides of leaves regularly from May onwards.
Powdery mildew
White powdery coating appears on leaves in warm, dry spells with poor air circulation; cut back affected growth hard, improve spacing, and water at the base rather than overhead; resistant cultivars should be chosen for humid gardens.
Vine weevil
C-shaped cream grubs eat roots below soil level, causing sudden wilting and plant collapse; treat with nematodes (Steinernema kraussei) in late summer when soil is warm, or use container-safe vine weevil compost.
Prevent ivan cranesbill problems before they start
Most ivan cranesbill issues are care-mismatch, not bad luck. Dial in the basics:
Ivan Cranesbill problems — FAQ
Why is my ivan cranesbill geranium sawfly (arge pagana)?
Larvae skeletonise leaves in late spring and summer, leaving papery patches; hand-pick caterpillars or apply a contact insecticide; inspect the undersides of leaves regularly from May onwards.
Why is my ivan cranesbill powdery mildew?
White powdery coating appears on leaves in warm, dry spells with poor air circulation; cut back affected growth hard, improve spacing, and water at the base rather than overhead; resistant cultivars should be chosen for humid gardens.
Why is my ivan cranesbill vine weevil?
C-shaped cream grubs eat roots below soil level, causing sudden wilting and plant collapse; treat with nematodes (Steinernema kraussei) in late summer when soil is warm, or use container-safe vine weevil compost.