The original grows in Columbia,SC without protection. I cover mine with plastic sheeting and place space heater in the enclosure with thermostat device to turn on heater when below freezing. It's too cold here and stays below freezing for too long for my citrus to live and hold fruit through winter. I'd say try to ask Ben Salley or Stan Mckenzie since they have large specimens and to my knowledge only use microsprinklers when freezing over night to protect their trees.