The One Thing Standing Between You and a Weed Invasion
You finally did it. After months of careful mowing, watering, and babying your lawn, it looks like something straight out of a golf course ad. Then, a few weeks later—BAM—crabgrass. Everywhere.
What went wrong? You skipped pre-emergent. Or worse, you used the wrong one.
Here’s the deal: pre-emergent herbicide stop weeds before they start, but only if you use the right type for your grass. Get it wrong, and you could be damaging your turf or letting weeds run wild. Let’s make sure that doesn’t happen.
Pre-Emergent 101: What It Actually Does (and Doesn’t Do)
First, let’s bust a myth: Pre-emergents do NOT kill existing weeds. If you see dandelions or chickweed already waving hello, you’re too late.
Instead, pre-emergents form a barrier in the soil that stops weed seeds from germinating. No germination = no weeds. But only if applied at the right time. More on that later.
Now, let’s talk about which pre-emergent is best for your lawn type.
If You Have Warm-Season Grass, Read This
Bermudagrass, Zoysiagrass, St. Augustine, Centipedegrass
Best picks: Prodiamine, Dithiopyr, Indaziflam
Avoid: Atrazine (for Bermudagrass), Isoxaben (for Centipedegrass)
- Prodiamine (a.k.a. Resolute 65 WDG)is the MVP for warm-season lawns. It stops crabgrass, poa annua, and other nasty invaders before they show up.
- Dithiopyris your backup plan—if you’re late on application, it can still prevent early-stage weeds from taking over.
- Indaziflamprovides long-lasting control for those who hate reapplying every few months.
Heads-up: St. Augustine and Centipedegrass can be sensitive. Always check the label before applying anything new.
Cool-Season Lawns Need a Different Strategy
Kentucky Bluegrass, Fescue, Perennial Ryegrass
Best picks: Prodiamine, Pendimethalin, Siduron
Avoid: Indaziflam (too aggressive for cool-season turf)
- Prodiamineis your go-to, offering broad-spectrum weed prevention without stressing out your grass.
- Pendimethalinworks great but needs precise timing—it’s not forgiving if you’re late.
- Siduronis the rare pre-emergent that lets you seed while still blocking weeds (perfect for overseeding projects!).
Pro tip: Cool-season lawns often need two applications—one in early spring, another in late summer—to stay weed-free year-round.
How to Apply Pre-Emergent Like a Pro
Even the best pre-emergent won’t work if you apply it incorrectly. Here’s the right way to do it:
- Time it right. Spring apps go down when soil temps hit 50-55°F. Fall apps go in before temps dip below 70°F.
- Measure carefully. More is NOT better. Overdoing it can damage your grass.
- Spread it evenly. Uneven application = patchy weed control.
- Water it in. A light watering (0.5 inches) activates the herbicide.
Common Mistakes That Ruin Everything:
- Applying too early or too late
- Skipping the watering step
- Using the wrong herbicide for your grass type
The Takeaway: Pick Smart, Apply Right, Enjoy a Weed-Free Lawn
The best pre-emergent herbicide is the one that fits your lawn’s specific needs. Choose wisely, apply correctly, and watch your lawn thrive while weeds wave the white flag.
Need the best pre-emergent for your grass? Check out your options while shopping for Pre-Emergent herbicides.