Star of Toscana is a cultivar of the species Trachelospermum Jasminoides. If anything I would say that the species (T. Jasminoides) is more hardy than the cultivar (T. Jasminoides Star of Toscana) but neither of them are very hardy! They are frost hardy and normally tolerate short spells down to -5C. It will require a sheltered position away from cold winds a south facing site is ideal. Trachelospermum is evergreen and it can be easily trained against a wall – but it is not self clinging so it will require training onto wires or some other support.