It also helps that the staff and/or interns made an attractive edging from spliced bamboo. Sometimes just a suggested barrier is good enough to keep people on the right paths.
I've noticed that this variety of sedum (although easy to break with a shoe or a frisbee) is a strong spreader in most gardens. It also blooms in some shade. I've planted mine under a limbed-up wax myrtle tree that sits close to where my 70lb dog likes to stick her nose through the perennial border. But even with canine curiousity nudging around its edges, my clump of 'Autumn Joy' sedum has grown large enough that I think I can rest easy.