I found it can survive -6 °C. But that's not clear, is -6 °C for 2 weeks still fine? Is -2 °C for a week still fine? In both cases, it means 24/7 frost, it's not the same as temporary temperature fall and day temperature above 0.
So far, after 3 day long 24/7 frosts -4 night and -2 day everything is fine, alive and still green, it looks healthy.
Do you have any experience with that?
After 3 days 24/7 frost and one week without frost:

I think it's damaged a bit, some leaves are black, what do you think?
Now (May 12):
