Troubleshooting
Broad-Petalled Cranesbill problems — and how to fix them
Broad-Petalled Cranesbill (Geranium platypetalum) 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.
Powdery mildew
Grey-white coating on leaves appears in hot, dry summers with poor air circulation; improve spacing, water at the base rather than overhead, and remove affected foliage promptly.
Vine weevil
C-shaped grubs feed on roots in late summer to autumn, causing plants to wilt and collapse; treat container-grown plants with nematodes (Steinernema kraussei) from August to October when soil temperature is above 5°C.
Prevent broad-petalled cranesbill problems before they start
Most broad-petalled cranesbill issues are care-mismatch, not bad luck. Dial in the basics:
Broad-Petalled Cranesbill problems — FAQ
Why is my broad-petalled cranesbill powdery mildew?
Grey-white coating on leaves appears in hot, dry summers with poor air circulation; improve spacing, water at the base rather than overhead, and remove affected foliage promptly.
Why is my broad-petalled cranesbill vine weevil?
C-shaped grubs feed on roots in late summer to autumn, causing plants to wilt and collapse; treat container-grown plants with nematodes (Steinernema kraussei) from August to October when soil temperature is above 5°C.