I sprayed my courgettes with milk and water every morning just to stop the white patches: three days later, what was showing on the new leaves told me I’d treated the wrong thing
Three days of faithful milk-and-water misting didn’t stop the white patches on courgette leaves—because there was nothing to stop. What looked like powdery mildew was actually harmless natural variegation, a discovery that came too late but teaches a crucial gardening lesson about diagnosis before treatment.