Excessive boron..and it takes very little to be excessive, will permanently damage your soil so that plants won't grow in that spot. It's generally not recommended. The alternative could be worst. You could use a post-emergent weed killer.

Here is a link that might be useful: Borax

Our new place is infested with this evil Charlie dude - I'm going to war pulling out piles but he keeps coming back! It's growing around, up, through, and over azaleas, junipers - even low spruces branches...I'm ready to call in air strikes.... I guess the options are simple - we either pull and pull and quit our jobs so we can keep pulling, or we blast with Roundup... like everyone, I'm wishing there was a better way.

Why pull. It's much better than grass and some other weeds. I use creeping Charlies as a ground cover in some of my beds. It doesn't bother anything taller. Iris's, tall lillies, clematis (they like their roots cool.) I planted a row of old fashioned iris and daylilly across the length of my garage and didn't leave room behind to mow or weed eat. I had a ton of grass. I let the creeping charlie grow and it has taken out almost all of the tall grass. It has not affected the plants. I think the leaves are pretty. I just don't grow short plants in those beds.

I have a love/hate relationship with creeping Charlie.It is a beautiful plant and a great ground cover.Now if it wasn't so bent on covering all the ground I would like it better. I'm just learning to live with it.