Agoseris lacksewitschii is pretty sparse-blooming in nature here. Wonder how it would do in captivity? I suspect it would be rather taller than one might wish for.
I've only grown Agoseris glauca, which bloomed nicely and was quite tall. Also, contrary to Flora of Alberta which describes it as tap-rooted, it sent up rhizomatous shoots about a foot and 18 inches or so away, so I actually turfed it in its second (I think, offhand) year.
Calgary, Alberta, Canada - Zone 3
-30 C to +30 C (rarely!); elevation ~1130m; annual precipitation ~40 cm
I'd probably be inclined to keep either away from the rock garden proper (by my limited definition, meaning a place for small plants) and put them in outlying meadow/berm etc areas, with other things I expect not to be small/tidy enough..lol. I know it's different on a city property, where you have to be more choosey re: space. I got some seed a while back of what I presume is one of the Agoseris, near Nordegg.
west central alberta, canada; just under 1000m; record temps:min -45C/-49F;max 34C/93F; http://picasaweb.google.ca/cactuscactus http://urbanehillbillycanada.blogspot.com/