Lawn in Middle Georgia

I live in central GA and have struggled with my lawn for years. Since there are a lot of trees on my lot I have found that St Augustine is my best choice but there are some sunny areas where I want Centipede to grow. They problem is that I have seeded areas with Centipede and put down sod only to watch over a couple of years for weeds and other grasses to take over and crowd out the Centipede completely. Some of these grasses look good in midsummer but die off quickly in August and creating bare spots.

I have tried fescues in these ares and in shady ares but it always dies out in Summer. I have read you can't use them in our area although they work fine 100 miles north in Atlanta.

My lot is hilly with lots of slope, and is completely sandy. I can push a rod 3 feet down with very little resistance.

Any and all advice welcome as I get ready to try again this spring.

If other grasses want to "take over and crowd out the Centipede completely", maybe you should encourage some of them. However, with the soil as sandy as you say, it may not be the choice of which grass variety to use, but the lack of organic matter and nutrients. Bare spots are common on lawns in the South, usually indicating the lack of nutrients to support them. Any grass is going to die out in that sort of situation, even the ones that originally were very competitive. Even if you apply well composted products like Kriket Krap on these bare spots, the rate of decomposition in the Georgia summer pretty much guarantees that you aren't going to have any organic matter left as soon as a year later.

I have built up a fairly robust lawn over the last 5 years, enough so that chickens can graze on it and it recovers in a week or two after the chicken tractor has been moved on. I have some centipede grass, but I also seed it with bahia grass and browntop millet. There is also a bit of bermuda grass, and while it can be a nasty invasive for some people, mine just stays in the background. I also sprinkle around some crimson clover in the fall as a soil building measure. It's off to a slow start this year, as February has been as cold as January.

I should mention that my soil is 6"-12" of clay loam on top of a solid clay subsoil, completely different from your very sandy soil, but both can suffer from lack of organic matter. I am using biochar to build up soil carbon in my garden, and haven't had enough to spare for just the lawn. However, at some point when I am up to my elbows in biochar, I could see working in an inch or two into the lawn. That would be organic matter that will not disappear after one Georgia summer.

I have lived here over 35 years and the situation I described intensified in the last few years. I fertilize twice most every year and have a sprinkler system. The main reason I posted is that in recent years some unidentified weed grasses now are taking over long standing centipede stands. I suppose that the trees are taller so I am dealing with more shade but its just curious that a good standby like centipede all of a sudden can no longer hold its on.

I am open to trying some bahiagrass against these intruders. Anyon have experience with the Argentine bahiagrass vs the more domestic varieties?