Many homeowners mow over crabgrass and call it part of the lawn. In his book, "1001 All-Natural Secrets to Pest Control, " Myles H. Bader writes "A weed is really just another plant that is unwanted in a specific area. It has similar characteristics as most plants. Some weeds are actually desired in gardens because of their colors. Many people keep certain weeds as part of their gardens." For homeowners who consider crabgrass a weed, there are ways to eliminate it without killing the yard.
Apply a pre-emergence herbicide in the spring before crabgrass plants seed. This is the most effective way to eliminate crabgrass. Follow the manufacturer's directions for proper application rates.
Spray the lawn with a post-emergence herbicide while the plants are young if crabgrass is already established in the lawn. These products won't kill the lawn. At your local garden center, look for a product that says crabgrass killer on the label. After seven days, spot-spray any crabgrass still growing. Post-emergence herbicides work well if the plants are caught at the right stage, but you may prefer to try some organic remedies first.
Kill the crabgrass with white vinegar for an organic remedy. Isolate the crabgrass and spray or pour 1/8 to 1/4 cup vinegar directly on the plant.
Set the trimming length on your lawn mower to 2 1/2 to 3 inches. Weeds need light to grow. By letting the grass grow taller, you shade the crabgrass and weaken it. The invasive lawn grass forces out the dying crabgrass. Try this method along with vinegar for more effectiveness.
Pull crabgrass by hand. If you do it right, it's quite effective. Make sure the ground is wet. When you pull on the crabgrass, do so with a slow tugging motion. You're trying to get all the roots along with the weed. Yanking on it will break the grass at the roots. If an open, bare spot remains, over-seed it with a grass seed, and keep the lawn mower on the right setting.