Re: Getting rid of ground cover
If an invasive has taken over your yard to the extent that you can't mow it, it is well beyond the recovery of any weed-n-feed or similar topical nuisance herbicide. Even if you could kill it in this manner, it has already choked out what grass was there, leaving you with bare ground once it's gone.
My recommendation is to start over. I would recommend using a sod cutter and getting rid of the nuisance invasive completely. From there it is your decision whether to rototill to amend and break up the soil or just roll out new sod over the top of the newly stripped ground. I personally like to amend the soil so as not to have to use topical fertilizers. Tilling also breaks up and aerates the soil, leading to healthier, happier grass.
I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!