Imagine this: You step out onto your lawn, ready to enjoy a perfect summer day, only to see tiny green sprouts popping up everywhere. Those aren’t the grass you wanted! Those are weeds, and they are stealing the beauty and health of your yard. Dealing with weeds is a frustrating, never-ending battle for homeowners everywhere.
Choosing the right pre-emergent herbicide feels like navigating a confusing maze. Should you use a granular product or a liquid? When is the exact best time to apply it? Pick the wrong product or apply it at the wrong time, and you might as well have done nothing at all. You end up wasting time and money, and those pesky weeds still win.
This guide cuts through the confusion. We will break down exactly what pre-emergents do, how to pick the perfect one for your specific lawn needs, and the simple steps to apply it correctly. By the end of this post, you will have the confidence to stop weeds before they even start growing.
Top Pre-Emergent For Lawns Recommendations
- Designed to prevent weeds; will not aid in eliminating existing weeds. Prevents grassy and broadleaf weeds, including crabgrass, poa annua, goosegrass, henbit, and more.
- Contains 0.48% of the active ingredient prodiamine for professional-grade weed control for early spring and fall applications
- Made with patented DG Technology (dispersible granule) ensures granules dissolve rapidly upon watering, moving weed control directly into the soil for maximum impact
- Small particles for more coverage per square inch and superior performance
- Made in the USA
- Designed to prevent weeds; will not aid in eliminating existing weeds. Prevents grassy and broadleaf weeds, including crabgrass, poa annua, goosegrass, henbit, and more.
- Contains 0.48% of the active ingredient prodiamine for professional-grade weed control for early spring and fall applications
- Made with patented DG Technology (dispersible granule) ensures granules dissolve rapidly upon watering, moving weed control directly into the soil for maximum impact
- Small particles for more coverage per square inch and superior performance
- Made in the USA
- Scotts Halts Crabgrass & Grassy Weed Preventer prevents the germination of listed lawn weeds so you can enjoy your lawn
- Prevents the germination of crabgrass, foxtail, spurge, barnyardgrass, and more as listed in the early spring all season long, and moss (except in California), Poa annua, henbit, corn speedwell, and chickweed in the fall
- Apply this pre-emergent weed killer in the early spring to a dry lawn or in the fall; rain, snow, or freezing weather after application will not affect the performance of this product
- This lawn care product is for use on all grass types (with the exception of Dichondra or Bentgrass)
- One 20.12 lb. bag of Scotts Halts Crabgrass & Grassy Weed Preventer covers 10,000 sq. ft.
- Prevent Weeds
- Effective Weed Prevention: Incorporating 0.37% PRODIAMINE into your lawn care routine ensures effective strategies for weed prevention, particularly targeting common weeds like crabgrass in the spring and poa annua (annual bluegrass) in the fall.
- Suitable for ALL GRASS TYPES: This product is suitable for use with various grass types, including Bahiagrass, Centipedegrass, Bermudagrass, Zoysia, St. Augustinegrass, Seashore Paspalum, and Tall Fescue (including turf-type), making it versatile for different lawn environments.
- CRABGRASS PREVENTION: It effectively prevents the growth of crabgrass, poa annua (annual bluegrass), and other common weeds, ensuring a healthier and cleaner lawn throughout the seasons.
- CANNOT SHIP TO MAINE OR IOWA**
- Prevents crabgrass and broadleaf weeds before they appear with Dithiopyr
- Covers up to 15,000 square feet, ideal for larger properties or repeated applications
- 0-0-7 fertilizer blend for added potassium and turf health
- Suitable for use in early spring or fall application windows
- Used by lawn care professionals and DIY homeowners alike
- Scotts WeedEx Prevent with Halts prevents crabgrass all season long
- This pre-emergent grassy weed killer stops crabgrass before it starts
- Apply in early spring for season-long prevention of crabgrass, or apply in fall to prevent winter weeds such as Poa annua, henbit, and chickweed
- Do not apply this lawn care product to Dichondra and Bentgrass
- One 10.06 lb. bag of Scotts WeedEx Prevent with Halts covers 5,000 sq. ft.
- Scotts Halts Crabgrass & Grassy Weed Preventer prevents the germination of listed lawn weeds so you can enjoy your lawn
- Prevents the germination of crabgrass, foxtail, spurge, barnyardgrass, and more as listed in the early spring all season long, and moss (except in California), Poa annua, henbit, corn speedwell, and chickweed in the fall
- Apply this pre-emergent weed killer in the early spring to a dry lawn or in the fall; rain, snow, or freezing weather after application will not affect the performance of this product
- This lawn care product is for use on all grass types (with the exception of Dichondra or Bentgrass)
- One 10.06 lb. bag of Scotts Halts Crabgrass & Grassy Weed Preventer covers 5,000 sq. ft.
Your Essential Guide to Choosing the Best Pre-Emergent for Lawns
Keeping your lawn green and weed-free is a big job. Pre-emergent herbicides are your first line of defense against springtime invaders like crabgrass. This guide helps you pick the right product for a healthier, happier yard.
Key Features to Look For
When shopping for pre-emergents, certain features make one product better than another. Focus on these:
- Active Ingredients: This is the chemical that stops the weeds. Common effective ingredients include Prodiamine, Dithiopyr, and Pendimethalin. Check the label to ensure it targets the weeds common in your area.
- Weed Spectrum: Does it only stop crabgrass, or does it handle other common weeds like spurge or chickweed? A broader spectrum offers better overall protection.
- Application Timing Window: Some products last longer than others. Look for a product that offers a long control period, usually 10 to 16 weeks.
- Lawn Safety: The product must be safe for your type of grass (e.g., cool-season vs. warm-season grasses). Always verify compatibility.
Important Materials and Formulation
Pre-emergents come in different physical forms. The material affects how you apply it and how quickly it works.
- Granular (G): These look like fertilizer pellets. They are easy to spread evenly using a standard spreader. They often need watering in after application to activate the chemical barrier.
- Liquid (EC or SC): These must be mixed with water and sprayed. They can sometimes absorb faster but require careful calibration of your sprayer to avoid over-application.
Factors That Improve or Reduce Product Quality
The quality of your pre-emergent isn’t just about the brand name. How the product performs depends on these factors:
Factors That Improve Quality:
- Longevity: A product that stays active in the soil longer means fewer applications throughout the season.
- Rainfastness: Once applied and watered in, the product needs to resist washing away during heavy rain. Good rainfastness ensures the weed barrier stays put.
Factors That Reduce Quality:
- Temperature Sensitivity: Some chemicals stop working well if the soil gets too hot. Check the recommended soil temperature for application.
- Improper Application: Applying too little product creates gaps where weeds can sprout. Applying too much can harm your turf.
User Experience and Use Cases
How easy is the product to use? A difficult product often leads to poor results.
Ease of Use: Granular products are generally favored by homeowners because spreading them is simple. If you choose a liquid, you need a reliable sprayer and good measuring skills. Read reviews to see how easily the product mixes or spreads.
Timing is Everything: Pre-emergents only work if they stop the seed *before* it sprouts. The best use case is applying them in early spring before soil temperatures consistently hit 55°F. If you wait until you see weeds, the product will not work. This is a preventative measure, not a cure.
Post-Emergent Combination: Some modern products combine a pre-emergent with a post-emergent (a chemical that kills existing weeds). These are great for lawns that already have a few scattered weeds when you apply the barrier.
10 Frequently Asked Questions (FAQ) About Pre-Emergent Lawn Care
Q: What exactly is a pre-emergent herbicide?
A: A pre-emergent stops weed seeds from sprouting roots and shoots. It creates a chemical barrier in the top layer of the soil.
Q: When should I apply my pre-emergent?
A: Apply it in early spring, usually before soil temperatures reach 55 degrees Fahrenheit consistently. Watch for when forsythia bushes start blooming; that is often a good sign.
Q: Can I use a pre-emergent if I plan to overseed my lawn?
A: Usually, no. Most pre-emergents stop *all* seed germination, including grass seed. You must use a special product labeled as “weed and feed safe for new seed” or wait until the new grass is established.
Q: How long does a single application last?
A: Most high-quality products offer control for 10 to 16 weeks. You might need a second application in mid-summer for long-season weeds.
Q: Do I need to water the product in after spreading?
A: Yes, almost always. Watering helps move the chemical barrier down into the top inch of the soil where weed seeds are waiting.
Q: Will pre-emergent kill my established lawn grass?
A: If you apply it correctly and it is labeled safe for your grass type, it will not harm established grass. It only targets sprouting seeds.
Q: What is the difference between granular and liquid forms?
A: Granular is easier to spread with a machine. Liquid must be mixed and sprayed evenly using a hose-end or backpack sprayer.
Q: Can I use pre-emergent in the fall?
A: Yes. Fall applications are very important. They stop winter annuals like henbit and help control summer weeds like crabgrass next spring.
Q: What if I see weeds already growing?
A: Pre-emergents will not kill visible weeds. You need a post-emergent herbicide to spot-treat the existing growth.
Q: Should I use a pre-emergent with fertilizer (Weed & Feed)?
A: These combination products work well, but only apply them when your lawn needs fertilizer. If your lawn does not need food, use a standalone pre-emergent.