Hello, I live in Kentucky close to the Tennessee border. I have Zoysia Grass in my yard started planting 32 years ago, I am now getting in spots a type of Bermuda grass, I think, and it is killing out my Zoysai and taking over, Whitman I do to get rid of it. I have tried spot weed killer but nothing seems to stop it. Please any advise will help.
Thank You
Chuckie51

If I knew the answer to that question I would be rich, because Bermuda grass is very invasive and spreading all over the US. There's no known way to keep Bermuda from invading quality lawns. You can hand pull it but the rhizomes will break off under ground and regrow.
I've seen people kill their lawn and re-sod only to have it invade in a few years. If you have super healthy Zoysia Grass and it covers your lawn very thick, it will discourage the bermuda but won't stop it. Good luck.