How to Get Rid of Crabgrass: Guide to a Weed-Free Lawn

Crabgrass (Digitaria spp.) a notorious annual weed, is a common nuisance in lawns, gardens, and paved areas. Known for its rapid growth and ability to produce thousands of seeds, it thrives in harsh conditions like compacted soil, heat, and drought, outcompeting desirable plants. Its resilience makes it a challenging adversary, but with a strategic combination of identification, manual removal, natural and chemical controls, and preventive lawn care, you can eliminate crabgrass and keep it from returning. This guide provides an in-depth explanation of how to get rid of crabgrass, covering natural methods, lawn-specific strategies, seasonal approaches, permanent solutions, and the best crabgrass killers that won’t harm your grass and help you achieve a lush, crabgrass-free landscape.

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

Prepare the Soil: Lightly water the area (or work after rain) to soften soil for easier root extraction.
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.
Dispose Properly: Place pulled plants in a sealed bag and discard in the trash to prevent seed spread. Do not compost.
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

Annual Pre-Emergents: Apply prodiamine or dithiopyr every spring for 2–3 years.
Complete Removal: Manually pull or use post-emergent herbicides to kill existing plants.
Prevent Seed Production: Remove crabgrass before it seeds in late summer.
Healthy Lawn: Maintain dense turf through proper mowing, watering, and fertilizing.
Soil Improvement: Test and amend soil for optimal grass growth.
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

Quinclorac (Drive XLR8): Effective post-emergent for young crabgrass; safe for most lawn grasses.
Mesotrione (Tenacity): Selective herbicide for pre- and post-emergent control; may temporarily whiten grass.
Fenoxaprop (Acclaim Extra): Targets crabgrass without harming cool-season grasses.
Prodiamine (Barricade): Top pre-emergent for preventing germination; long-lasting.

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.

Conclusion

Learning how to get rid of crabgrass requires a strategic, multi-faceted approach tailored to your lawn’s needs and the season. Start with accurate identification, then use manual removal, natural methods like corn gluten meal, or selective herbicides like quinclorac or mesotrione. Prioritize long-term prevention with a healthy lawn through proper mowing, watering, and soil care. By combining seasonal strategies and consistent effort over 3–5 years, you can deplete the seed bank and enjoy a crabgrass-free lawn. Monitor regularly, act early, and adapt your approach for lasting results.

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!