We get as cold as 17° but this winter the low was 25° for a short stretch around the new year and it was below freezing till noon for a few days. All our Salvia officinalis including our 'Tricolor' cultivar have made it without any bother. A few died but not in the winter. Some just fail to thrive. It should be hardy downin to zone five. I don't think that would be same if in a pot. I have cooked with all of them with one exception that being S. officinalis subsp. lavandulifolia which has an aroma of Rosemary. I will try it eventually. The others are all about the same to me and they all make me hungry when I smell them. It works great as a color echoed in your pot.
