Choose a post emergent herbicide to kill the actively growing grass. Keep the soil moist until the grass blades reach about two inches in height.
The university of florida extension service recommends re emergent herbicides that contain bensulide benefin prodiamine or oryzaline for control of weeds in bahia grass.
How to get rid of weeds in bahia grass. Hot weather grasses such as bahia and floratam are easily damaged by post emergent herbicides. Applying a post emergent herbicide will rid your bahia grass lawn of broadleaf weeds like knotweed lespedeza and spurge which are already in place. Mowing is very effective at weed suppression in seedling bahiagrass and will suppress both grassy weeds and broadleaf weeds whereas the safe herbicides such as 2 4 d will only affect the broadleaf weeds.
Spray the herbicide on your lawn as per the package directions. As the grass grows cut back on the number of times of watering per day but lengthen each session time to approximately 20 minutes. Let the crab grass go until the following spring and then use a preventer at the right time.
Use post emergence killer once crab grass shows up in your lawn you have three options. Hand pull the clumps to prevent the plant from reseeding itself. Sugar others have found success with dissolving white sugar over the weed.
Baking soda some people have had luck with using baking soda for killing dollar weeds. A full and healthy bahiagrass lawn crowds out weeds. This is supposed to kill the weeds but be safe for the grass.
The first application of herbicide should take place when the bahiagrass is small and just beginning to grow. As mentioned bahia grass will yellow when iron is deficient in your soil. These herbicides should only be applied when your bahia grass is healthy and temperatures are in the 60 to 85 degree range.
Start the mowing and fertilizing schedule once the blades become 3 inches tall. Is there any product available that will kill control the weeds but not damage the bahia grass. I have a lawn service but the tech told me there was nothing available that would kill the weeds without also damaging the bahia.
The most effective way of treating weeds that are invading your lawn is to use pre emergent herbicides that keep weeds under control by preventing germination. So i usually start with the mowing and that takes care of the weeds. Simply wet down the dollar weed foliage and sprinkle baking soda over it leaving it overnight.
With that strategy my lawn will eventually become all weed. Apply a post emergent herbicide in may.