In my part of north central Texas it is nearly always a container plant. It's not reliably winter hardy here and a really cold spell kills them. We usually manage one or two of those spells that would be too cold. Good warm location and heavy mulch helps, but is still not enough sometimes. But I'm located about 4 counties north of Copperas Cove and definitely get some colder temps off and on. I'd still think a good mulch or protection would be in order for some cold systems that blow down from Canada.
