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How to Get Rid of Crabgrass in Lawn: A Comprehensive Guide

June 12, 2024

Picture this: you're standing on your lush, green lawn, admiring the fruits of your hard work. But wait, what's that? Are patches of coarse, unsightly grass interrupting the uniformity of your meticulously maintained yard?

Chances are, you've fallen victim to the notorious crabgrass invasion. Fear not, dear homeowner, for in this comprehensive guide, we'll explore effective strategies on how to get rid of crabgrass in lawn once and for all.

How to Get Rid of Crabgrass in Lawn: A Comprehensive Guide, EZ-FLO™ Injection Systems

Understanding Crabgrass: The Unwelcome Guest

Before we dive into the battle plan, let's take a moment to understand our adversary. Crabgrass (Digitaria spp.) is an annual grassy weed that thrives in warm, dry conditions. It gets its name from its distinctive spreading growth pattern, resembling the legs of a crab. This tenacious weed can quickly take over your lawn, competing with your desired grass for nutrients, water, and space.

The Lifecycle of Crabgrass

The lifecycle of crabgrass, an annual weed, begins in late spring or early summer when soil temperatures reach 55-60°F (13-15°C). Seeds that have remained dormant in the soil germinate and quickly establish themselves, taking advantage of warm, dry conditions.

Crabgrass grows rapidly, producing numerous tillers and spreading through a prostrate growth habit. A single plant can produce up to 150,000 seeds during its lifecycle. As temperatures cool in fall, the mature plants die off, leaving bare lawn patches.

However, the seeds remain viable in the soil for several years, waiting for the right conditions to germinate and start the cycle anew. Understanding this lifecycle is crucial for implementing effective control strategies, such as applying pre-emergent herbicides in early spring and maintaining a healthy, dense lawn to prevent crabgrass from establishing itself.

How to Get Rid of Crabgrass in Lawn:

Prevention: The Best Defense

The old adage goes, "An ounce of prevention is worth a pound of cure." When it comes to crabgrass, preventing its establishment is far easier than eradicating it once it has taken hold. Here are some proactive measures:

  • Maintain a healthy, dense lawn: Your first defense against crabgrass is a thick, well-maintained lawn. Mow your grass at the proper height (typically 2.5-3 inches) and avoid scalping, as this can weaken your lawn and create openings for crabgrass to invade.
  • Apply pre-emergent herbicides: Timing is crucial when it comes to preventing crabgrass. Apply a pre-emergent herbicide in early spring before soil temperatures reach the germination threshold. These herbicides create a barrier that prevents crabgrass seeds from sprouting.
  • Overseed and fertilized: Overseeding your lawn in the fall helps fill in bare spots and thicken your grass, making it more resistant to crabgrass invasion. Additionally, proper fertilization promotes a healthy, robust lawn that can outcompete weeds.

Post-Emergent Herbicides: The Chemical Solution

Post-emergent herbicides can be an effective solution when hand-pulling crabgrass isn't feasible due to the extent of the infestation. These herbicides are designed to kill crabgrass plants that have already emerged from the soil and are actively growing in your lawn. Here's what you need to know about using post-emergent herbicides for crabgrass control:

Choosing the Right Herbicide

Look for post-emergent herbicides specifically labeled for crabgrass control. Some of the most effective active ingredients include:

  • Quinclorac: Found in products like Drive XLR8, quinclorac is highly effective against crabgrass at various growth stages. It's safe for use on most cool-season turfgrasses.
  • Fenoxaprop: Herbicides containing fenoxaprop, such as Acclaim Extra, are effective against crabgrass and goosegrass. However, they may be less effective on mature crabgrass than quinclorac.
  • Mesotrione: Mesotrione, the active ingredient in Tenacity herbicide, is a systemic herbicide that controls crabgrass and other grassy weeds. It can be used on both cool-season and warm-season turfgrasses.

Always read the product label carefully to ensure it suits your grass type, and follow the recommended application rates.

Timing and Application

For best results, apply post-emergent herbicides when crabgrass is actively growing and in its seedlings to the early tillering stage. Depending on your location, it is typically in late spring to early summer. Some key application tips:

  • Apply herbicides on a calm day to minimize drift onto desirable plants.
  • Ensure the lawn is dry and no rain is expected for at least 24 hours after application.
  • Avoid mowing for a few days before and after treatment to allow maximum leaf surface for herbicide absorption.
  • Use a calibrated sprayer or spreader to apply the product evenly, following label instructions for mixing and application rates.
  • Wear protective clothing, gloves, and safety glasses when using herbicides.

Remember that post-emergent control may require multiple applications spaced 2-3 weeks apart for complete crabgrass eradication. Be patient and persistent.

Precautions and Considerations

While post-emergent herbicides can be highly effective, there are some precautions to keep in mind:

  • Some products may temporarily discolor or stunt desirable turfgrasses, especially when applied in hot weather or to stressed lawns.
  • Avoid using "weed and feed" products that combine herbicides with fertilizers, as the timing for each may not align optimally.
  • Use caution with non-selective herbicides like glyphosate, as they will kill any vegetation they contact. Spot-treat only the crabgrass to avoid damaging your lawn.


In conclusion, ridding your lawn of crabgrass requires a multi-faceted approach that combines prevention, eradication, and proper cultural practices. By understanding the nature of this weed and implementing the strategies outlined in this guide, you'll be well on your way to achieving a crabgrass-free lawn that is the envy of the neighborhood.

Remember, success lies in consistency and patience. Stay vigilant; you'll soon enjoy a lush, weed-free lawn showcasing your dedication and hard work.

Frequently Asked Questions:

Can I use a post-emergent herbicide on my entire lawn to control crabgrass?

It's essential to choose a post-emergent herbicide that is specifically labeled for crabgrass control and safe for your particular grass type. Applying a broad-spectrum herbicide indiscriminately can harm your desired grass.

Can I overseed my lawn in the spring to help control crabgrass?

While overseeding is beneficial for lawn health, it's best done in the fall. Spring overseeding can be less effective, as the new grass seedlings may struggle to compete with the aggressive growth of crabgrass during the warmer months.

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