How do you kill johnson grass in centipede grass?

To kill johnsongrass in centipede grass, you can use a selective herbicide containing glyphosate or a pre-emergent herbicide specifically designed to target grassy weeds. Apply the herbicide carefully, ensuring it only affects the johnsongrass and not the centipede grass. Timing is crucial; apply during the active growth period of johnsongrass for the best results. Additionally, maintaining healthy centipede grass through proper mowing, watering, and fertilization can help it outcompete the johnsongrass.