Our lawn was sodded with bermuda celebration a bit more than 4 years ago. Prior to installation, very little fill was added over existing thin soil which is on limestone. I can push a screw driver into the ground about 3" on average before hitting rock.

The ~8000 SF lawn was somewhat neglected over the first 3 years during which I did not fertilize. It did receive regular irrigation during the Texas summer, though less than 1"/week.

The lawn is now full of weeds, most of which out grow the bermuda in height, and many of which seem to have flourished over the last few months. I put down CGM last month, though many weeds were already established. The top of bermuda is generally below my lowest setting on the mower, so scalping just reduces weed height.

I understand that in organic lawn care the best defense (and maybe offense) against weeds is a taller turf, but my bermuda is so low (and I believe celebration is meant to be kept short), that I cannot figure out how to shade out or smother the weeds! In the one area of lawn where I have more significant fill, the grass grows tall, and requires very little irrigation. Weeds are very extensive in the few areas that receive regular watering by the septic sprayers.

I'm at a loss as how to proceed, short of herbicide or spraying vinegar. They are too widespread to use a weedhound. I liberally applied alfalfa and milorganite (combined about 1 lb nitrogen) a week ago in hopes of kickstarting the bermuda.

I would appreciate any advice on how to proceed. I would like to top dress at least twice in the coming year, but really feel I need more grass height (and growth) first.

Thank you!