Oh, MY GOSH!!!
A couple of years ago I threw some of this sedum into one of my large back beds. Last year it spread some but it was so dry it didn't do much. After the rains this winter and spring it's decided it wants to live there without any neighbors! Any body need a ground cover for a bank or somewhere nothing will grow away from other plants? This stuff is climbing my plants!!!!
It was also a pain in the butt to pull up all the limelight artemesia.
I used to say, "not here" when people told me that things took over when all it needed was water.