How to Get Rid of Crabgrass in Your Lawn for Good

Many homeowners want to know how to get rid of crabgrass once it takes over a lawn. This fast-spreading weed grows in thin, bare or stressed turf. One plant can drop thousands of seeds, so it returns every year. Fortunately, you can beat it with the right timing and a few good habits.

What Is Crabgrass?

Crabgrass is an annual grass weed. It sprouts in spring, grows all summer and dies with the first hard frost. However, before it dies, it scatters seeds that wait in the soil for next year.

You can spot it by its wide, light-green blades and low, sprawling growth. The stems spread outward like crab legs, which gives the weed its name.

How to Get Rid of Crabgrass: The Two-Part Plan

Success depends on two things. First, you stop new seeds from sprouting. Second, you remove the plants that already grow. Use both methods for the best results.

Step 1: Apply a Pre-Emergent Herbicide

A pre-emergent herbicide forms a barrier in the soil. It stops crabgrass seeds from sprouting. Timing matters here. Apply it in early spring, when soil temperatures reach about 55°F for several days in a row. Many people watch the forsythia and lilac bushes. When the forsythia blooms fade, it is usually time.

Water the product in lightly, and avoid disturbing the soil afterward. Do not apply it if you plan to seed the lawn, because it also blocks grass seed.

Step 2: Pull Small Infestations by Hand

If you only have a few plants, pull them out. Do this after rain, when the soil is soft. Grab the plant at the base and remove the whole root system. Then fill the hole with soil and grass seed so weeds cannot return.

Step 3: Use a Post-Emergent Killer for Larger Areas

Large patches may need a post-emergent herbicide. Choose a product labeled for crabgrass and safe for your grass type. Apply it while the weeds are young, because mature plants resist treatment. Always read the label, and follow the temperature and watering directions.

Prevent Crabgrass With Better Lawn Care

Crabgrass thrives where grass is weak. A thick, healthy lawn blocks sunlight and leaves little room for weeds. Therefore, good habits are your best long-term defense.

• Mow high. Keep the grass at three to four inches. Taller grass shades the soil.
• Water deeply. Soak the lawn once or twice a week instead of sprinkling daily.
• Fertilize on schedule. Feed cool-season grass in early fall for the strongest roots.
• Overseed thin areas. Fill bare spots each fall. Our guide on when to plant grass seed explains the best timing.
• Keep mower blades sharp. Clean cuts help grass recover faster.

Common Mistakes to Avoid

Several errors can undo your hard work. For example, many people apply pre-emergent too late. Others scalp the lawn with a low mowing height. Also, some water too lightly, which encourages shallow roots.

The U.S. Environmental Protection Agency offers guidance on responsible landscape watering through its WaterSense outdoor program.

When Should You Reseed After Removing Crabgrass?

Wait until late summer or early fall. By then, crabgrass is dying back and soil temperatures favor new grass. Seeding in fall gives the new turf time to establish before winter.

Final Thoughts

Learning how to get rid of crabgrass comes down to timing and lawn health. Apply a pre-emergent in early spring, remove plants that slip through and grow thick turf. Stay consistent for a season or two, and your lawn will look greener every year.