Use Weed-B-Gone for Southern Lawns to kill broadleaf weeds like dandelions. For grassy weeds the only grass killer herbicide products will kill the bahia, too. Once you get rid of the broadleaf weeds, you can evaluate what you have left. Then you can try to shield the existing bahia from overspray by covering it with cardboard. Spray the rest of the grassy weeds with Grass-B-Gone or RoundUp. You should be left with lots of dead spots. Then water those spots lightly every day for a week. The idea with that watering is to sprout any unsprouted weed seeds. Then use the appropriate weed killer on those new weeds. If you spot spray RoundUp (shielding if you need it) on the last round, you can rake up the dead stuff and seed the new seed right away.

When you spray herbicides, you are not trying to drench the soil. All you need to do is get a mist to stick to the leaves or blades of the plants you're trying to kill. If the herbicide beads up on the leaves, add a few drops of shampoo or dish soap to help it stick to the weed.

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