sedum acre could be considered a beautiful, invasive but easy to control groundcover. It is shallow rooted and quite easy to just pull up. Recommended. I also have variegated sedum (mediovarigatum- sp?) that is yellow and green and about 10" tall that makes a good companion.
Sedum matrona is a large purple beauty that will make a tall ground cover if you let it!
I have a light green with that was the throw-back color that grew with the variegated white one (forgot name) I separated it out and it is lovely
I need more! Does anyone have a good online source for plants?