I know that, but had to try... got a little jar of Christmas moss I wanted to highlight, my spider wood, in my nano... the package said perishable, but not "live plants" , and when I received them, they were frozen, I put the hockey puck of them in the nano, just in case ( I've never had Christmas moss, and know nothing about it ), but assume it's dead... I have some Frog bit coming as well, expect that will be the same, so the lil tank will be devoid of green, except the Hoya vines growing out of it, until spring, and warmer temps arrive... fish get shipped over night, plants go ground, and without heat packs, so there is much more time to get exposed to freezing temperatures