I was doing some research on sedums and found these links interesting. The Horticulture agent says to continue as you are but you report that..... it ain't working! LOL!

"Sedum Control
Submitted by JoCoEMG on July 30, 2007 - 10:49am.

Sedum should not be that difficult to control as it has very fibrous habit. If you dig the clumps they should not come back. A spot treatment of shoots with a Roundup type product may also help.

But from my experiences with sedum I would simply dig the shoots and remove. If it is that quick spreading and hard to control are you sure it is sedum?

A word of caution when using Roundup products do not have it come in contact with other plants.

Dennis Patton
Horticulture Agent
Johnson County K-State Research and Extension"

and this other one is about sedum herbicides:
http://www.ehow.com/list_7554033_herbicides-sedum.html

Here is a link that might be useful: Sedums

I usually do not like adding herbicides if I can help it so is there some way to make life miserable to these pesky plants without harming the C/H? Less water? More acidity? Cover them with 1" or 2" thick carpet of newspapers (use rocks to keep them in place on windy days)?

Thank you Luis ~ I don't use either if I could help it, those potent chemicals ~ only sparingly on the Q Aspen tree roots that crawled & wandered where they could even after the tree had been taken down years ahead!

I did some search as well & ran into the Sedum Scty ~ the collection was beautiful ~ but these 3 here that seem to multiply faster than even Periwinkle are too hoggy! I just hope that Climbing H Anomala's twines w/ rootlets can find their way to latch on hopping over the sedoms!!! I'll just keep on plucking, I guess UGH!!!