Introduction
Frustrated by patches of coarse, weedy grass that stand out like a sore thumb in your otherwise green lawn? Crabgrass is one of the most common—and annoying—lawn weeds homeowners battle each year. But the good news is, with the right approach, you can prevent and control it without having to spend every weekend on your hands and knees pulling weeds. This complete guide will show you how to control crabgrass in your lawn, step by step, using smart, sustainable lawn care practices that keep your turf thick, healthy, and naturally crabgrass-free.
Why Crabgrass Control Matters for a Healthy Lawn
Crabgrass is an annual weed that thrives in thin, bare, or stressed areas of your lawn. It germinates in spring when soil temperatures reach about 55°F–60°F, grows fast in hot weather, and drops thousands of seeds that return next year if left unchecked.
Crabgrass:
- Crowds out desirable grass by stealing sunlight, water, and nutrients.
- Weakens your lawn’s root system.
- Leaves unsightly bare patches when it dies off in fall, inviting more weeds.
By learning to control crabgrass naturally—and combining it with healthy soil, mowing, and watering habits—you can grow a dense lawn that shades out crabgrass before it even starts.
Step-by-Step Guide to Controlling Crabgrass
Step 1: Understand When Crabgrass Germinates
Timing is everything. Crabgrass seeds sprout when soil temperatures stay around 55°F–60°F for several days—often in early to mid-spring, depending on your region.
✅ Pro tip: Watch for local forsythia blooms. When these shrubs bloom, it’s usually the right time to apply pre-emergent controls.
Step 2: Use a Pre-Emergent Weed Preventer
A pre-emergent herbicide stops crabgrass seeds from sprouting by creating a barrier in the top layer of soil.
- Apply a pre-emergent in early spring before crabgrass seeds germinate.
- Use a broadcast spreader for even application.
- Water lightly to activate the product.
- Avoid disturbing the soil afterward—raking or aerating can break the barrier.
✅ Natural option: Corn gluten meal is an organic pre-emergent that can help suppress crabgrass seeds. It won’t kill existing crabgrass but can reduce seed germination when applied properly.
Step 3: Pull Young Crabgrass by Hand
If you spot small crabgrass plants:
- Pull them up before they go to seed.
- Grab at the base and get the entire root to prevent regrowth.
- Use a weeding tool for tougher spots.
Hand-pulling is easier early in the season while plants are still small.
Step 4: Mow High to Shade Out Crabgrass
Mowing too short is like rolling out the red carpet for crabgrass seeds.
- Set your mower to the highest recommended setting for your grass type (usually 3–4 inches for cool-season grasses).
- Taller grass shades the soil, making it harder for crabgrass seeds to get the light they need to sprout.
- Follow the one-third rule: never remove more than one-third of the grass blade height at a time.
Step 5: Water Deeply and Infrequently
Frequent, shallow watering favors weeds like crabgrass.
- Water deeply (about 1 inch per week) to encourage deep, healthy roots.
- Water early in the morning to reduce evaporation and disease risk.
- Use a rain gauge or tuna can to measure your sprinkler’s output.
Step 6: Fill Bare or Thin Spots Promptly
Crabgrass loves bare soil. The thicker your lawn, the fewer places crabgrass seeds have to grow.
- Overseed thin areas in fall for cool-season grasses or late spring for warm-season grasses.
- Use the same grass type as your existing lawn.
- Top-dress with compost to improve seed-to-soil contact.
- Keep new seed consistently moist until established.
Step 7: Improve Soil Health to Build a Stronger Lawn
Healthy soil grows healthy grass that naturally crowds out weeds.
- Aerate compacted soil annually to help roots grow deep.
- Top-dress with compost once or twice a year.
- Fertilize appropriately—avoid over-fertilizing, which can encourage crabgrass.
- Test your soil’s pH every few years and adjust if needed (most turfgrasses thrive at pH 6.0–7.0).
How to Spot Treat Existing Crabgrass
If crabgrass gets ahead of you:
- Spot-treat mature patches with a post-emergent herbicide labeled for crabgrass. Follow label instructions carefully to avoid harming your grass.
- For a more natural approach, dig out larger plants with a weeding tool or shovel.
- Don’t compost pulled crabgrass if it has seeds—dispose of it in the trash.
Common Mistakes to Avoid
Mistake #1: Missing the Pre-Emergent Window
Applying pre-emergent too late won’t stop crabgrass seeds that have already germinated. Solution: Apply when soil temps hit 55°F–60°F consistently.
Mistake #2: Mowing Too Short
Scalping your lawn weakens grass and gives crabgrass an advantage. Solution: Mow high to shade the soil.
Mistake #3: Disturbing Soil After Pre-Emergent
Raking or aerating after applying pre-emergent breaks the barrier. Solution: Do any dethatching or aerating before you apply.
Mistake #4: Overwatering or Watering Shallowly
Too much or too little water stresses grass and favors crabgrass. Solution: Water deeply and infrequently.
Mistake #5: Ignoring Bare Spots
Every bare spot is a seedbed for crabgrass. Solution: Reseed and overseed thin areas each year.
Extra Lawn Care Tips & Hacks
✅ Use a Soil Thermometer
Soil temps, not air temps, matter for crabgrass germination. A cheap soil thermometer keeps you ahead of the game.
✅ Grasscycle Your Clippings
Leaving clippings on the lawn helps shade soil and retain moisture, which discourages crabgrass seeds from sprouting.
✅ Check Sprinklers for Even Coverage
Uneven watering causes thin spots that invite crabgrass. Inspect your system each season.
✅ Check Out Our Overseeding Guide
Want to thicken your lawn to crowd out weeds? Don’t miss our complete guide on how to reseed your lawn for thicker grass for lush, dense turf.
Conclusion
Crabgrass might be persistent, but it doesn’t stand a chance against a healthy, thick lawn. Learning how to control crabgrass in your lawn naturally comes down to good timing, smart soil care, proper mowing, and consistent watering.
By combining a pre-emergent plan, regular overseeding, and healthy maintenance, you’ll build a resilient lawn that shades out crabgrass and other weeds before they ever take hold.
Bookmark this guide and revisit it every spring to get ahead of crabgrass for good—your lush, green lawn will thank you!