I assume it’s not very cold hardy but I don’t like having big potted trees in my house 8 months out of the year, so I decided to take a chance and put it in a portable greenhouse last winter and treated it like my other hardy citrus that are in ground using two water barrels and two small 250 watt space heaters regulated by thermo cube, and it did fine even overwintered this fruit without damage. However, it was a very warm winter I think only getting to 14 degrees F in mid March. If I am supposed to go to single digits I will probably freak out and dolly cart it into the living room.