A spot herbicide for weed control is effective at killing crabgrass and not grass, but it depends on the type of herbicide. Always check the label to ensure that your herbicide is safe for grass but tough on crabgrass. Overall, spot treatment is ideal because it puts fewer herbicides into the soil, which can damage the soil. If you’re wanting a natural remedy to crabgrass that also won’t harm surrounding grass, you can also hand-remove crabgrass or even pour boiling water or 5% vinegar over crabgrass as a spot treatment.

Mowing your grass regularly, especially if you’re mowing close to the ground, can help kill Johnsongrass. Frequent mowing helps limit the spread of Johnsongrass and can even deplete carbohydrate reserves in rhizomes over time. The more time you leave in between mowing, the more likely Johnsongrass is to regrow and take over your lawn. 

Yes, suggesting companion planting and mulching to minimize new growth.

Each type of weed comes with its own control methods, but stopping the seed spread is the first step. Grazing, mowing, and hand pulling can slow the invasion. In some cases, selective herbicide is necessary to stop a persistent weed from overtaking an area.