How to Get Rid of Crabgrass

If you want to know how to get rid of crabgrass for good, you’re in the right place. Crabgrass (Digitaria spp.) is a resilient annual weed that spreads aggressively, producing up to 150,000 seeds per plant that can lie dormant in soil for 3–7 years. It thrives in heat, drought, and compacted soil — stealing space from your lawn before you realise it. This guide covers every proven method: manual removal, natural solutions, targeted herbicides, and a long-term prevention plan so crabgrass doesn’t come back next season.

What Is Crabgrass and Why Is It a Problem?

Crabgrass is a notorious annual weed that spreads quickly, producing up to 150,000 seeds per plant that can remain viable in soil for 3–7 years. Its resilience makes it a formidable opponent in lawns and gardens, particularly in areas with thin grass or poor soil health. Understanding its characteristics is the first step to effective control.

Key Features of Crabgrass

  • Appearance: Grows in low, spreading clumps with wide, flat blades in a star-like pattern, resembling crab legs. Young plants are light green, turning reddish-purple as they mature.

  • Growth Habit: Germinates in spring, thrives in summer, produces seeds, and dies with the first frost.

  • Common Locations: Found in lawns with sparse grass, garden beds, sidewalk cracks, and compacted soil.

  • Distinct Traits: Stems radiate from a central point, seed heads form finger-like spikes, and it has a shallow root system.

Pro Tip: Misidentifying crabgrass as quackgrass (a perennial weed) or tall fescue (a desirable grass) can lead to ineffective treatments. Always confirm its star-like growth pattern before acting.

How to Identify Crabgrass in Your Lawn

Accurate identification is crucial to avoid harming desirable plants. Compare crabgrass to similar plants:

  • Crabgrass vs. Quackgrass: Quackgrass has deeper roots and is perennial, while crabgrass is annual with shallow roots.

  • Crabgrass vs. Tall Fescue: Tall fescue has broader blades and is a desirable lawn grass, unlike crabgrass’s star-like clumps.

Identification Checklist:

  • Look for low, spreading clumps with light green to reddish-purple blades.

  • Check for finger-like seed heads in late summer.

  • Confirm shallow roots when pulling.

How to Get Rid of Crabgrass Manually

Manual removal is ideal for small infestations or organic gardening. It’s labor-intensive but effective when done correctly.

Step-by-Step Manual Removal

  1. Prepare the Soil: Lightly water the area (or work after rain) to soften soil for easier root extraction.

  2. Pull the Plant: Grasp crabgrass at the base and pull slowly to remove the entire root system. Use a hand trowel or weeding fork for larger plants.

  3. Dispose Properly: Place pulled plants in a sealed bag and discard in the trash to prevent seed spread. Do not compost.

  4. Repair Bare Spots: Fill with grass seed, sod, or mulch suited to your climate (e.g., Kentucky bluegrass for cool-season areas, bermudagrass for warm-season areas).

Best Timing: Early spring or early summer, when plants are young and roots are small.

Tools Needed: Hand trowel, weeding fork, garden gloves, sealed disposal bags.

Tips:

  • Work in small sections to avoid fatigue.

  • Check weekly for new sprouts to prevent seed production.

Natural Methods to Get Rid of Crabgrass

For eco-conscious gardeners, natural methods can control crabgrass without chemicals. These are most effective for small patches or as part of an integrated approach.

1. Corn Gluten Meal

  • How It Works: Acts as a natural pre-emergent, inhibiting seed germination by releasing nitrogen.

  • Application: Spread 20 pounds per 1,000 square feet in early spring (soil temperature 50–55°F). Water lightly to activate.

  • Pros: Safe for pets, children, and the environment; enriches soil.

  • Cons: Requires precise timing; may affect desirable grass seeds.

2. Horticultural Vinegar

  • How It Works: 10–20% acetic acid burns crabgrass foliage, killing or weakening the plant.

  • Application: Spot-spray young crabgrass on sunny, dry days. Avoid nearby grass or plants.

  • Pros: Non-toxic and widely available.

  • Cons: Non-selective; less effective on mature plants.

3. Boiling Water

  • How It Works: Scalds crabgrass in non-lawn areas like pavement cracks.

  • Application: Pour directly onto plants, avoiding desirable vegetation.

  • Pros: Simple and chemical-free.

  • Cons: Impractical for large areas; may not kill deep roots.

4. Mulching

  • How It Works: A 2–3-inch layer of organic mulch (wood chips, straw, bark) smothers crabgrass and blocks sunlight.

  • Application: Apply in garden beds, using weed-free mulch. Replenish annually.

  • Pros: Enhances soil health and aesthetics.

  • Cons: Not suitable for lawns.

Note: Combine natural methods with lawn care practices for best results.

How to Get Rid of Crabgrass in Your Lawn

Lawns require targeted strategies to eliminate crabgrass while preserving desirable grass. Here’s how to tackle it effectively.

Pre-Emergent Herbicides

  • Purpose: Prevent crabgrass seed germination.

  • Timing: Apply in early spring (soil temperature 50–55°F for 3–5 days, typically March–April).

  • Products: Prodiamine (Barricade), dithiopyr (Dimension), pendimethalin (Pendulum). Check grass compatibility.

  • Application:

    1. Mow to 2.5–3 inches for even coverage.

    2. Apply granular or liquid herbicide with a calibrated spreader/sprayer.

    3. Water lightly (0.25–0.5 inches) to activate.

    4. Avoid disturbing soil to maintain the herbicide barrier.

  • Note: Delay lawn seeding for 6–12 weeks after application.

Post-Emergent Herbicides

  • Purpose: Kill actively growing crabgrass.

  • Timing: Apply in late spring/early summer when crabgrass is small (2–4 leaves).

  • Products: Quinclorac (Drive XLR8), mesotrione (Tenacity), fenoxaprop (Acclaim Extra).

  • Application:

    1. Spot-treat with a pump sprayer for precision.

    2. Apply on a calm, dry day (below 85°F).

    3. Avoid mowing 1–2 days before/after application.

  • Note: Some herbicides may temporarily whiten grass, but it recovers.

Lawn Maintenance Tips

  • Mowing: Keep blades at 3–4 inches to shade soil.

  • Watering: Provide 1–1.5 inches weekly in 1–2 deep sessions.

  • Overseeding: Sow grass seed in thin areas to create dense turf.

  • Aeration: Aerate annually to reduce soil compaction.

  • Fertilization: Use slow-release fertilizer (e.g., 10-10-10) in spring/fall.

Seasonal Strategies for Crabgrass Control

Spring

  • Apply pre-emergent herbicides to stop germination.

  • Manually remove young crabgrass.

  • Overseed thin lawn areas to build density.

Summer

  • Use post-emergent herbicides on young crabgrass.

  • Pull plants before seed heads form.

  • Maintain high mowing height and deep watering.

Fall/Winter

  • Clean up dead crabgrass and debris.

  • Apply pre-emergents in late winter (February–March) in mild climates.

  • Aerate and overseed for a strong spring lawn.

Winter Prep:

  • Test soil pH (aim for 6.0–7.0) and amend as needed.

  • Apply mulch to garden beds to suppress spring germination.

How to Kill Crabgrass Permanently

Permanent elimination is challenging due to crabgrass’s persistent seed bank, but a multi-year strategy can minimize its presence.

Long-Term Plan

  1. Annual Pre-Emergents: Apply prodiamine or dithiopyr every spring for 2–3 years.

  2. Complete Removal: Manually pull or use post-emergent herbicides to kill existing plants.

  3. Prevent Seed Production: Remove crabgrass before it seeds in late summer.

  4. Healthy Lawn: Maintain dense turf through proper mowing, watering, and fertilizing.

  5. Soil Improvement: Test and amend soil for optimal grass growth.

  6. Vigilant Monitoring: Inspect weekly in spring/summer for new sprouts.

Timeline: Expect 3–5 years of consistent effort to deplete the seed bank.

Best Crabgrass Killers That Won’t Harm Your Lawn

ProductTypeBest ForGrass Safe?
Quinclorac (Drive XLR8)Post-emergentYoung crabgrass (2–4 leaves)Most lawn grasses
Mesotrione (Tenacity)Pre & post-emergentBroad controlCool-season grasses
Fenoxaprop (Acclaim Extra)Post-emergentCool-season lawnsYes (cool-season)
Prodiamine (Barricade)Pre-emergentPreventing germinationMost grasses

Safety Tips:

  • Wear protective gear (gloves, eye protection).

  • Keep pets/children off treated areas until dry.

  • Follow label instructions for dilution and timing.

Common Mistakes to Avoid

  • Delaying Action: Late summer seed production worsens infestations.

  • Misapplying Herbicides: Incorrect timing or dosage reduces effectiveness.

  • Neglecting Lawn Health: Thin lawns invite crabgrass.

  • Overusing Chemicals: Excess herbicides can harm grass or soil.

When to Call a Professional

If crabgrass persists or covers large areas, consider a lawn care professional for:

  • Expert assessment of soil and lawn issues.

  • Commercial-grade herbicide applications.

  • Tailored maintenance plans.

Find Professionals: Contact local lawn services or extension offices for recommendations.

Frequently Asked Questions

Q: Does pulling crabgrass spread it?

A: It can if the plant has already produced seed heads. Always pull crabgrass before late summer when finger-like seed spikes appear. Dispose of pulled plants in a sealed bag — never compost them.

Q: Will crabgrass die on its own?

A: Yes — crabgrass is an annual weed and dies naturally with the first autumn frost. However, it will have already dropped thousands of seeds by then, guaranteeing a fresh infestation next spring unless you act.

Q: What kills crabgrass permanently?

A: No single application kills crabgrass permanently due to its persistent seed bank. Consistent use of pre-emergent herbicides for 2–3 years, combined with dense turf maintenance, is the closest to a permanent solution.

Q: Can I use vinegar to kill crabgrass?

A: Horticultural vinegar (10–20% acetic acid) can burn young crabgrass foliage but is non-selective and will damage surrounding grass. Use it only for spot treatments in cracks or garden beds, not on lawns.

Q: When should I apply pre-emergent for crabgrass?

A: Apply when soil temperature consistently reaches 50–55°F for 3–5 days — typically March to April in most US regions. A good rule of thumb: apply when forsythia shrubs begin to bloom in your area.

Conclusion

Knowing how to get rid of crabgrass is only half the battle — consistency is what wins the war. Start with accurate identification, then choose the right removal method for your situation: hand-pulling for small patches, corn gluten meal or horticultural vinegar for an organic approach, or targeted herbicides like quinclorac or mesotrione for larger infestations. Build a healthy, dense lawn through proper mowing (3–4 inches), deep weekly watering, and annual aeration, and you’ll crowd out crabgrass naturally over time. With a disciplined seasonal plan and 3–5 years of pre-emergent applications, you can deplete the seed bank and reclaim your lawn for good.

Start your crabgrass control plan today! Test your soil, apply pre-emergents in spring, and maintain a healthy lawn year-round. Share your tips or questions in the comments below!