I know that on the West Coast, types of Palm Trees can grow (I am not sure if these are natural or just transplanted) as far north as Vancouver, BC, in Canada. I have heard that on the East Coast they occur naturally as far North as North Carolina. I have no idea about central North America.
So my question is what is the northernmost point that Palm Trees grow naturally on the East Coast, West Coast and in the centre of the continent, and what is the northernmost point on the East Coast, West Coast and Central that they can survive in if transplanted?
Lets say with natural conditions, that is, the climate is capable of supporting them without humans watering them, ect.