I bought a 'Pink Swirl' on sale last fall and kept it in a container but it died over winter. It was "cold" for zone 7, and even though it never got below 5F, the roots froze in the container.
I got another one from Santa Rosa this spring, and I was surprised to see it bloom this year, even during a very dry summer. It's planted in the ground now so the roots will be protected this winter.