Vinca has been experimentally controlled by hand - pulling and herbicide treatments .
Threats to the species include invasive plant species , particularly plants that form thick groundcover , such as ice plant ( Carpobrotus chilensis ) and vinca ( Vinca major ) .
Vinca major has been experimentally controlled by hand - pulling and herbicide treatments .
Threats to the species include invasive plant species , particularly plants that form thick groundcover , such as ice plant ( Carpobrotus chilensis ) and vinca ( Vinca major ) .