Thanks for your interesting question. Ajuga is a member of the mint family and like all mints it likes to spread. They spread by runners in the soil as well as by seeds sometimes. If not taken care of they can and do become unruly/invasive as you have seen.

I have listed a couple of links which may help you in understanding your problem. Basically your options for removal/control depending on the severity of the Ajuga is: hand removal or use of a herbicide (synthetic or organic). If using a herbicide remember to read and follow the label direction! Also selection of the herbicide is important as the wrong on can kill the grass as well. One should be selected that targets Ajuga/Bugle. If the spread in your law is extensive you may need to do a total sod replacement.

Removal will be a continuous task as the plants roots left in the soil a viable to produce new starts. I regret that I did not have better news but Ajuga as with all mint family members if left unchecked can become a problem as you are finding out.

I have also listed your County OSU Extension Office which you may want to contact for possible additional help or advice. Again thank you for allowing us to assist you in your horticulture concerns.

Thank you for allowing us to help you with your gardening questions. Here are some other helpful websites:
BYGL Newsletter: http://bygl.osu.edu/
OSUE FactSheets: http://ohioline.osu.edu
State Master Gardener Volunteer website - http://mastergardener.osu.edu

Montgomery County OSU Extension Office

580 Calumet Lane

Dayton, Ohio 45417

Phone:<personal data hidden>

Fax:<personal data hidden>

Link:

Visit the Montgomery County Office website

https://www.gardeningknowhow.com/ornamental/foliage/ajuga/how-to-control-ajuga-plants.htm

https://plants.ces.ncsu.edu/plants/ajuga-reptans/