Since the enzymes responsible for cell growth in broad-leafed plants are different from the enzymes responsible for grassy plants, herbicides target and disrupt the enzymes in weeds while leaving grass enzymes alone. This ultimately destroys all the weeds without causing any harm to the lawn grass....
You can kill unwanted weeds by pouring hot, boiling water on and around it, up to a 3-foot radius in order to address the root system. Be aware, though, thatboiling water will harm and kill healthy grass and other plants around the crabgrass. Will boiling water kill trees? Killing tree...