Can't help with the hardiness info, just wanted to say that I'm growing a tender sedum as a houseplant (Sedum morganianum,donkey tail sedum) so even if you find S. pulchellum to not be hardy, all is not lost - you can just add to your houseplant collection.

I have Sedum morganianum as a houseplant too, I guess I can take cuttings in the fall just in case.

Sharon

I planted a Sedum pulchellum last year. Bought a 4" pot in full magnificent bloom, but was a little surprised that it later sort of disappeared. About the only way I could describe it was that it "bloomed itself to death". Looking around on the internet now, I see it's considered on some sites to be a biennial, so that might actually explain its behavior.

Theoretically, zone 6-9, according to the info on the plant tag.
I don't expect to see any trace of it next year, but I'll keep an eye out.
Apparently native to Kansas, Oklahoma...interesting.

Did it flower and set seed for you before it disappeared Lori?

Gardens North does rate it as Zone 4 and says that it tends to be monocarpic or biennial as you say, but self-perpetuates. It is indeed a very appealing sedum.

Sharon

Yes, as I mentioned, it bloomed like mad, presumably set seed, then after a while it died...just like a biennial in its second year, or a monocarpic species (or an annual, for that matter) ...so the web and Gardens North analyses seem accurate. So, I don't expect to see any trace of the original plant, though perhaps there will be some seedlings.