Our yard is nearly totally taken over by Creeping Charlie and I had to use Dicamba, despite its dangers to other plants. (I have tried to be careful in using it). Despite this, the roots still seem alive after a week. Since the grass is of poor quality anyway, I am willing to completely turn the page and put new sod or totally reseed. Would it be safe to now mow what is left (including some areas where Creeping Charlie is still alive)? Or would that just cause the spread of the flower, which most of them still have on them at this time of the season, to other areas? Many thanks for your help.
While creeping charlie does spread by seed, its most aggressive form of propagation is by stolons. Mowing should not affect these.
If you decide to reseed, I would wait until early fall, at the end of August to do this. This is a bad time to try to get seeds growing. And if you do start over, you should first kill the creeping charlie with a couple of applications of glyphosate (Roundup).
You should determine why the creeping charlie took over. If it is too much shade, you should expect the same thing to happen when you reseed. Grass needs 6-8 hours of full sun to thrive. By careful pruning, sometimes it is possible to get more sunlight into an area. But another approach is to grow something else - a ground cover or shade-loving easy-care perennials. Here are some references: