I sprouted some from the super market last summer and put it in the ground around fall. I was afraid it wouldn't get established enough before winter, but the stems that were partially buried from the mulch are still green. I'm not sure exactly how hardy they are, but we actually had snow here and they seem find.

They haven't sent up new shoots yet (along with several other of my gingers) and I'm hoping it's still alive. I just rooted them in regular potting soil and they seem to grow really well when it's hot and humid. I have mine growing in partial shade, but they may need more sun than that.

They seem to grow well in Southern California. I noticed that it needs good draining soil. Cooler weather may not be a problem but bad draining soil and wet winters will probably kill it. I had a few failed attempts(they would just rot in winter) until I found the right spot in my yard.