Its, perennial vinca. Sounds like you have the white variegated variety (I've got the yellow, my,self). MOW it, it will keep it in check and really make you feel better. You won't kill it, I promise.

Now, if you want to kill it, why not try and see if anyone on the plant exchange forum will give you something you want for it instead. If you trade away much of it, but still want to kill it, ask again and I'll tell you how.

~Chills

Chills- thanks! no I do not want to kill it- good idea about posting it but there is so much there I didn't think anyone else would want it! I als have some that is oval shaped with yellow veins in it with blue flowers, would that be the yellow or is that something else? the runners are yellow too.

could be. I've got the yellow and it has sections where the leaves are almost entirely yellow. Without pictures, definite identification is difficult, but it could be.

I've seen people successfully trade off ditch lilies and comfrey (both extremely common here), so who knows what someone will want.

~Chills