Dear Cherie, Sagina subulata grows on the Isle of Skye and if it can survive there it can survive anywhere! Skye is on the west coast of Scotland and there are other islands beyond (north of it), the biggest one is called the north pole! It is beautiful there and the flora & fauna is incredible, but so is the cold in the winter! It is also famous for Bonnie Prince Charlies Liqueur "Drambuie'.
When we got married the landlord on our Honeymoon kept giving Sarah large ones of this on the house, she can't remember anything at all, until I showed her a bed of Daffodils she fell in on the way home. Perfect shape of Sarah, in the flattened Daffodils!
When N.A,S.A. need an extra boost for a spacecraft they get some 'Drambuie', it is smooth, honey filled rocket fuel!
By the way your Sagina subulata is sometimes called Scottish moss but is not a true moss! The common name over here and as I know it by is, Irish moss as it grows there a lot.
Regards.
Neil.
p.s.
Isle Of Skye! Click here