Blue Star spreads by rhizomes and one of the easiest to propagate and obvioulsy it likes the mositure, not too wet that it gets now, possibly because of the lawn watering so you may nto be able to cut back on the watering. For repacement of the lawn area that it has overtaken I can see no option of ridding of the grass without disturbing the creeper so you might want to dig up the plants and pot to baby and then sufficate the lawn either with cardboard or other means and then replant the creeper. The following link shows how to propagate plants that spread by rhizomes.

Here is a link that might be useful: Propagating Perennials

Well, I'm slowly doing the same thing. What I've done is covered the lawn in cardboard (several layers) and put nursery soil on top. I put the blue star creeper into that. It's taking off pretty well. Grass is hardy stuff and it isn't giving up without a fight, but I"m winning. BTW - the creeper does go dormant in the winter, at least here. Good luck!

Can I buy blue star creeper seeds? If so where? I want it everywhere in my yard! Thanks

Great gc when in bloom, but not reliably winter hardy for me, so I don't replant anymore here.