Not as hardy as caerulea-Minimum say -5°C 23°F but more importantly it does not do well in the ground unlike the other violaceas-so I suggest growing it in a pot and keep it quite potbound.
Check the link below to be sure the plant ID is correct-it has very distinctive foliage.
Myles

Here is a link that might be useful: Passiflora Eynesford Gem