MEDITERRANEAN SURVIVABILTY INDEX ZONE 5B: The Heated Greenhouse Zone
From Palmpedia - Palm Grower's Guide
This zone is one which one would have to have a very well heated greenhouse to get these palms to survive at all and these palms may not even survive a month or two outdoors, even in summer in a Mediterranean climate.
Cyrtostachys renda (this is even difficult to grow well in a greenhouse in most Mediterrean climates, unless it is very well heated) Pigafetta elata and filaris Phoenicophorum