Up at the lake I have the area that's next to the gravel road that has the worst soil since the grater shoves the gravel into the area. I planted low lying sedums, ajuga and ribbon grass and it grows like crazy. It's holding the gravel up at the road and not letting it waah down the hill into the remaining flower bed (entire hill is a flower bed).

Gold Moneywort or Golden Creeping Jenny. The same thing just two different names. It grows like crazy and is a bright golden color. It has yellow flowers, but they are hardly noticeable.

I've never used it myself, but I have heard that gro-lo sumac is good for that situation. Ours friends used it on a steep slope in front of their house and are happy with it.

Sedum...you really do not have to worry about it...also the creeping jenny...even moneywort if it is surrounded by cement, that will filling quickly...
If you would like some sedum I am also in St Paul and have plenty to share

I have 2 beautiful beds of Pacysandria (sp?) that I brought to Minnesota with me from Pennsylvania. Another name for it is Allegheny Spurge-which might tell me something I dont want to know! It is lovely, thick no care. I did sink some edging around it to keep it out of the lawn. another ground cover I like is Vinca/Myrtle. It has lovely blue flowers, takes sun or shade.