Glechoma hederacea, creeping Charlie or ground ivy. Can be a real pest!

Thanks for identifying. Online I am reading that a simple application of weed b gone will kill it. I will try that but, for long term, any idea how to prevent this from continuously creeping over? There are some areas where my lawn is very thick and healthy and it still creeped over.

That is a commonly held fallacy....that a lush lawn will deter any weeds :-) It just doesn't work that way, especially when dealing with a monoculture like any suburban lawn is. The only effective way of keeping it from spreading or invading is installing some sort of barrier between your neighbor's yard and yours. And even that may not produce 100% control as it will germinate easily from seed.

I have a fence separating our yards but, as youre aware that hasnt helped. I am thinking of maybe digging a small trench next to the fence and applying a mixture of post emergent and mulch in the trench. I'll do some more research as i dont like to jump straight into using chemicals.

Using a weed killer will only take care of the symptoms. It is not a cure. If it hasn't already spread to far I would definitely use some sort of barrier or border to keep it on the neighbors side. Also, try not to cut it with a weed trimmer or lawnmower. This weed spreads very easily and using these types of power equipment will only help it reach other parts of your lawn. If it is a small area I would dig the roots up and burn it. I have seen this weed take over in a shady area where grass once existed. Changing the ph of the soil in that area would also help deter the weed from spreading.

www.lawncaremadeeasy.com

It will grow in the same pH range most turf grasses require (slighty acidic to neutral) so not sure what possible impact altering the soil pH (which is extremely difficult to do on any permanent basis anyway) would have..........