LAWN PHIX PRO TIPS
Crabgrass control is all about timing. This annual grassy weed germinates in the spring when soil temperatures hit 55°F for three consecutive days, and it thrives during the hot summer months. Here’s the exact 3-step method I use on my property and for all of my Lawn Phix customers to keep lawns crabgrass-free all season.
Step 1: Early Spring Pre-Emergent (First Week of April)
Apply a pre-emergent containing Prodiamine evenly across your lawn to prevent crabgrass seeds from germinating. Use one of the following:
- 0-0-7 with 0.37% Prodiamine (granular): Apply 5 lbs. per 1,000 sq. ft.
- 18-0-3 with 0.38% Prodiamine (granular): Apply 4-5 lbs. per 1,000 sq. ft.
- Barricade 4FL (liquid): Apply 0.5 oz. per 1,000 sq. ft.
Step 2: Late Spring Pre-Emergent (Six Weeks After Step 1)
Follow up with a pre-emergent containing Dithiopyr (Dimension) to extend your crabgrass prevention. Choose from these options:
- Dimension 2EW (liquid): Apply 0.5 oz. per 1,000 sq. ft.
- 21-0-10 with 0.25% Dimension (granular): Apply 3-4 lbs. per 1,000 sq. ft.
Pay special attention to hot spots like driveways, sidewalks, and curb lines. These areas heat up faster, making them prime locations for early crabgrass breakthroughs.
Step 3: Post-Emergent Control
If crabgrass breaks through later in the summer, treat it with a post-emergent herbicide containing Quinclorac. I recommend:
- Drive XLR8 (liquid): Mix 1.45 oz. per gallon of water with a non-ionic surfactant for maximum effectiveness.
Table of Contents
How To Get Rid Of Crabgrass (Kill + Prevent Crabgrass)
Crabgrass is one of the most stubborn weeds I deal with at Lawn Phix. It thrives in hot weather, spreads aggressively, and can quickly overtake even a healthy lawn. But with the right approach, you can prevent it from taking hold and effectively eliminate existing plants. Here’s how I help my customers keep crabgrass at bay, and how you can do the same.
What is Crabgrass?
Crabgrass is a warm-season annual grassy weed that germinates in the spring and thrives during hot, dry summers. It gets its name from its “crab-like” appearance: low-growing with a central stem and radiating blades resembling crab legs.
Each year, crabgrass seeds are shed in the late summer and fall, lying dormant in the soil until spring temperatures reach 55°F for several consecutive days. Once it germinates, crabgrass grows quickly, competing with your turfgrass and producing thousands of seeds to restart the cycle next year.
How to Identify Crabgrass
Identifying crabgrass early is crucial to controlling it. Here’s what to look for:
- Growth Habit: Crabgrass grows low to the ground, spreading outward with broad, flat blades.
- Color: A lighter green than most lawn grasses.
- Seed Heads: Crabgrass seed heads appear late in the growing season, making it easy to identify mature plants.
- Common Locations: Crabgrass often appears along driveways, sidewalks, and curb lines—hot spots where soil heats up faster.
How to Kill Crabgrass
If crabgrass is already established, here’s how to tackle it:
Use Post-Emergent Herbicides
Selective post-emergent herbicides are your best bet for killing crabgrass without damaging surrounding grass. I recommend products containing Quinclorac, such as Drive XLR8, for cool-season lawns.
- Timing: Apply herbicides when crabgrass is actively growing but still young (early summer).
- Tips: Mix the herbicide with a non-ionic surfactant to improve absorption and effectiveness.
For mature crabgrass, Fenoxaprop-p-ethyl (Acclaim Extra) can be effective, but multiple applications may be needed.
Hand-Pulling
If the infestation is small, you can hand-pull crabgrass plants. Be sure to remove the entire root system to prevent regrowth. This method is most effective when the soil is moist.
Avoid Over-Treatment
Overuse of herbicides can damage your lawn and stress desirable grass types. Always follow product label directions and avoid treating drought-stressed lawns.
How to Prevent Crabgrass
Preventing crabgrass is easier than removing it. Here’s what I recommend:
Apply Pre-Emergent Herbicides
A well-timed application of pre-emergent herbicide is the most effective way to stop crabgrass before it starts.
- Timing: Apply in early spring when soil temperatures approach 55°F. In New England, this is typically in early April.
- Products: Use Prodiamine (Barricade) or Dithiopyr (Dimension). Both are highly effective at preventing crabgrass seeds from germinating.
- Pro Tip: For full-season control, follow up with a second application in late spring or early summer.
Maintain a Healthy Lawn
A thick, healthy lawn naturally crowds out weeds like crabgrass.
- Mow High: Keep your grass at 3-4 inches to shade the soil and discourage weed germination.
- Fertilize Regularly: Apply a balanced fertilizer to promote dense turf and strong root development.
- Fill Bare Spots: Overseed thin areas in the fall to prevent crabgrass from taking hold the next season.
Improve Soil Conditions
Crabgrass thrives in compacted soil and areas with poor drainage. Aerating your lawn in the fall improves soil structure and encourages healthy grass growth.
FAQs About Crabgrass
What will kill crabgrass but not the lawn?
Selective herbicides like Quinclorac or Dithiopyr target crabgrass without harming most cool-season grasses.
Why is my lawn full of crabgrass?
Crabgrass thrives in thin turf, compacted soil, and areas with bare patches. Addressing these issues with overseeding and aeration will help reduce infestations.
Is it better to pull or spray crabgrass?
For small infestations, hand-pulling is effective. For larger outbreaks, use selective post-emergent herbicides.
Can you permanently get rid of crabgrass?
While you can’t eliminate crabgrass seeds entirely, maintaining a dense, healthy lawn and applying pre-emergents annually will minimize its presence.
When should I apply a crabgrass preventer?
Apply pre-emergent herbicides in early spring before soil temperatures reach 55°F to prevent crabgrass seeds from germinating.
Conclusion
Crabgrass may be a persistent lawn weed, but with the right strategies, you can keep it under control. Focus on prevention, maintain a healthy lawn, and act quickly when crabgrass appears. At Lawn Phix, I’ve seen how combining proper timing and effective products like Prodiamine and Quinclorac can transform a crabgrass-infested lawn into a thick, lush, weed-free turf.
Ready to tackle crabgrass this season? Start now and take the first step toward a healthier, greener lawn!
