The Best Four Products for Killing Weeds Without Killing Grass
Are you trying to kill weeds without harming your grass? You're not alone. Whether you're chasing that golf course green or just trying to rescue your turf from a weed invasion, selective herbicides are your best bet, and we have the best options laid out for you.
🌱 Quick Takeaways
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Use selective herbicides designed for your grass type to avoid lawn damage.
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The Celsius and Certainty Herbicide Kit with Surfactant and Dye is best for warm-season grasses like Bermuda, St Augustine, Centipede, and Zoysia.
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The Tenacity and SedgeHammer Herbicide Kit with Surfactant and Dye is ideal for cool-season grasses like Tall and Fine Fescue, Perennial and Annual Ryegrass, and Kentucky Bluegrass.
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Manual weeding and a strong lawn care routine offer long-term weed prevention.
Keep reading to learn how the weed killers featured in this guide work and why lawn care pros trust them for safe, effective weed control.
Why Some Weed Killers Damage Lawns
Many general-purpose weed killers like glyphosate are non-selective — they kill everything, including your prized turf. Instead, you need a weed killer for lawns that’s selective, meaning it targets weeds without damaging your grass.
Related: 10 Common Mistakes to Avoid When Using Weed Killers
Weed Control for Lawns
The most effective long-term solution for controlling weeds is to have a healthy lawn in the first place. Fertilizers, biostimulants, and soil moisture managers can help keep your lawn in fighting form. Mowing your lawn regularly at the recommended height for your grass type is a natural way of controlling weeds. If the turf is healthy and flourishing, weeds have difficulty competing with grass for nutrients and resources.
Despite your best efforts, weeds can be pretty stubborn. A surefire way to get rid of weeds without killing grass is to pull them up manually. But, to initially target weeds quickly and effectively, herbicides can help kill weeds without damaging your lawn.
Related: What Types of Weeds Look Like Grass?
Best Weed Killers That Won’t Harm Your Lawn
You can choose from two categories of chemical weed control: liquid or granular. Both types have their disadvantages and their advantages. For example, liquid weed control products can kill weeds quickly. In most cases, results are seen within a few days. The downside is that strong and fast-acting chemicals like glyphosate are more likely to destroy your grass.
Remember, the objective with weed killers is to buy time to grow a healthy lawn.
So, which weed killers can you use that won’t kill grass?
We’ve made the job easy for you by rounding up the four safest weed killers for lawns. Certain plants favor certain conditions, and weeds are no exception. We’ve separated the best weed killer products into two categories: warm-season and cool-season herbicides.
Warm-Season Grass Herbicides
Some weeds prefer the warmer weather, germinating in the spring or early summer and dying back in the fall as the weather gets colder. For instance, many broadleaf weeds thrive in the warmer months. Using a herbicide specially formulated for these seasonal weeds will increase the effectiveness of the application without killing your grass.
Celsius WG Broadleaf and Grassy Weed Control
Celsius WG Herbicide is one of the most effective post-emergent weed killers for lawns with broadleaf and grassy weed problems. Ideal for treating existing weeds, it comes in wettable granule form that mixes with water to create a powerful spray solution.
Designed for warm-season grasses like Bermudagrass, Zoysiagrass, St. Augustine, and Centipede, Celsius targets over 150 weed species, including dandelions, clover, and spurge, without damaging your turf.
Unlike many herbicides that can stress grass in hot weather, Celsius remains safe and effective even at higher temperatures, making it a go-to solution for summer weed control in southern lawns.
For the ultimate warm-season grass herbicide partnership, combine Celsius with Certainty Turf Herbicide. This extends the range of weeds targeted by application to control sedges, Poa Annua, and much more.
Application
Apply using a battery sprayer or pump sprayer according to instructions. To increase product effectiveness, combine with a non-ionic surfactant, which helps increase herbicides' absorption, sticking and translocation.
TOP TIP: Resist the urge to mow your lawn immediately after applying this product or before the spray has dried. For best results, wait 2 days after spraying herbicides before resuming mowing. Also, avoid transferring grass cuttings to healthy turf areas when you mow your lawn.
Don’t water Celsius WG into your turf after application. It should be sprayed and allowed to dry.
Certainty Herbicide — Best Herbicide for Lawn Weeds Like Sedge
Certainty Herbicide boasts easy application for killing weeds in your lawn. A measuring spoon is included with the product to ensure accuracy and consistent results. This herbicide targets weeds such as Poa Annua, dandelions, and nutsedge. The clue is in the name!
Much like Celsius, one of the most significant benefits of using Certainty is that you can apply it over a broad range of temperatures without harming your grass or compromising effectiveness. Eliminate weeds in the spring, summer, and fall by using Certainty with Celsius WG Herbicide for the ultimate weed control.
Application
Again, the best way to apply this product is with a battery or pump sprayer. For 1000 ft of turf, use three to five small scoops or one to two large scoops per gallon of water. Don’t water Certainty into your turf after application.
For convenience, we offer Celsius and Certainty, along with marker dye and surfactant in a complete warm-season grass herbicide kit.
Cool-Season Grass Herbicides
Weeds, like most plants, love a bit of warm weather. Others thrive in cooler conditions, like Rescuegrass, Clover, Henbit, and Poa Annua. Luckily, weed killers are available that kill cool-season weeds without damaging your grass. These herbicides are most commonly used on Fescue (Tall and Fine), Kentucky Bluegrass, and Ryegrass (Perennial and Annual) lawns. Golf Course Lawn Store has got your back!
Tenacity Herbicide — Best Lawn Weed Killer for Overseeding
Tenacity herbicide is an industry favorite for killing weeds in your lawn without killing your grass. Optimized for cool-season turf, Tenacity can be used as a pre- and post-emergent herbicide control for over 46 broadleaf weed and grass species.
Tenacity’s active ingredients include Mesotrione (40%), a photosynthesis suppressant in receptive weeds as it becomes absorbed through roots, leaves, and shoots. With proven efficacy rates against weed invasion, Tenacity can kill hardy weeds like dandelions before and during turf seeding.
Application
You can use Tenacity herbicide at any point during the seeding or overseeding of established grasses. Post-application, weeds usually die within three weeks of application, turning white from chlorophyll loss. Tenacity comes with an integrated measuring cup for accurate and easy measuring. Use a backpack sprayer with this TeeJet foliar spray tip for the best results. One eight-ounce bottle will cover one to two acres of your lawn, and you’ll only need to water this in if you’re using it as a pre-emergent while seeding.
If you’re making a post-emergent application with Tenacity, we recommend using a non-ionic surfactant and marker dye so you can easily see where you’ve already sprayed the herbicide.
TOP TIP: If you see your turfgrass turning white, don’t panic. This is common but temporary. Typically, this occurs between five to seven days post-application and can sometimes last several weeks. Tenacity herbicide can be used on most cool-season grasses and some warm-season grasses (Centipede, Buffalograss), but do not apply to these grass types, as it will damage or kill them:
❌ Bentgrass
❌ Kikuyu Grass
❌ Zoysiagrass
❌ Seashore Paspalum
❌ Bermudagrass.
SedgeHammer® Herbicide — Nutsedge Weed Killer
SedgeHammer® is a safe, selective weed killer that doesn’t kill the grass. It targets infuriating weeds like yellow and purple nutsedge, kyllinga, and certain broadleaf weeds.
SedgeHammer® herbicide contains the highly concentrated active ingredient: Halosulfuron-methyl (75%,) which inhibits cell division in particular weeds, especially sedges. This weed killer comes as a water-dispersible granule (WDG), so it needs to be mixed with water for application. Since this weed killer doesn’t kill grass, it can work a little slower, showing results in up to 21 days — just remain patient!
Application
SedgeHammer® comes in a 1.33 oz bottle with a measuring scoop provided. You can add one level scoop to one gallon of water, covering 1,000 sq. ft. The entire bottle can cover approximately 43,500 sq ft.
Use a battery sprayer or pump sprayer to apply this professional formulation. You can also combine SedgeHammer® with Tenacity herbicide if you want an extra weed-killing boost for specific sedge problems.
Our complete cool-season herbicide kit includes SedgeHammer®, Tenacity, High-Yield non-ionic surfactant, and a marker dye.
Boost Herbicide Performance
Other products will give you a head start in achieving your golf course lawn, along with herbicides. Surfactants like Hi-Yield Spreader Sticker increase the absorption, sticking, and translocation of insecticides, liquid fertilizers, and herbicides. Surfactants help improve the performance of herbicides and yield faster and better results.
Marker dyes are also useful in your war against weeds. Use Turf Mark Blue Spray Indicator dye to see where you’ve sprayed herbicide, insecticide, or fungicide. This means you won’t be applying excess product in places that you have already sprayed. The dye disappears within 24-48 hours, so you don’t need to worry about turning your lawn, sidewalk, or patio blue permanently.
Related: The Best Weed and Feed for Your Lawn
Controlling Poa Annua and Trivialis
To control Poa Annua in Fescue, Ryegrass, and Bentgrass lawns, go with Velocity PM herbicide. This herbicide cleans up Poa Annua in just two easy applications.
Need to Kill Crabgrass?
If the primary weed you're targeting is crabgrass, Quinclorac DF is an excellent choice. This herbicide can be safely applied on the following grasses: Bermudagrass, Kentucky Bluegrass, Buffalograss, Tall Fescue, Ryegrass and Zoysia.
Related: The Best Crabgrass Weed Killers That Won’t Kill Your Turfgrass
When to Apply Weed Killer to Your Lawn
Apply herbicides when weeds are actively growing, and the forecast is clear for at least 24 hours. Avoid mowing right before or after application — wait 48 hours for best results.
Let them dry completely before walking on the lawn or letting pets out. When in doubt, wait until the next day.
Lawn Weed Control: Frequently Asked Questions
Q: Can I use weed killer right after fertilizing my lawn?
A: It’s best to wait at least 5–7 days after fertilizing before applying a weed killer. This gives your grass time to absorb nutrients without risking chemical stress from herbicide interaction.
Q: Should I water my lawn after using weed killer?
A: It depends on the product. Most post-emergent herbicides like Celsius or Tenacity should not be watered in. However, pre-emergent products may require watering to activate them. Always check the label.
Q: Will weed killers affect new grass seed?
A: Yes, most herbicides can harm new seedlings if applied too soon. Avoid using weed killer for at least 3–4 weeks after seeding unless it’s a product like Tenacity, which is seed-safe when used correctly.
Q: How do I get rid of weeds in shaded areas of my lawn?
A: Weeds in the shade often thrive due to thin grass. Use shade-tolerant grass seed, mow higher, and apply selective herbicides like SedgeHammer® or Tenacity, depending on your grass type.
Q: Can I combine different herbicides?
A: Some combinations — like Celsius with Certainty or Tenacity with SedgeHammer® — are safe and effective when used with a surfactant. Always read the label and combine only as directed to avoid turf damage.
Q: How long does weed killer stay active in the soil?
A: Most selective herbicides break down within a few weeks to months, depending on the product and environmental conditions. Avoid planting new grass or flowers in treated areas until the label’s replanting window has passed.
Win the Weed War
If you’ve read this far, you're serious about winning the war on weeds, and I love to see that. Whether you're dealing with stubborn sedges, broadleaf invaders, or just trying to keep crabgrass in check, there's a smart solution out there that won't wreck your turf.
Selective herbicides like the ones we've covered give you a powerful edge, but the real secret sauce is consistency. Stay on top of your mowing, fertilizing, and spraying, and you'll build a lawn so dense and healthy that weeds won’t stand a chance.
Take your time, apply carefully, and don’t forget to enjoy the process. A golf course lawn isn’t built in a day — but with the right tools, it’s absolutely within reach.
If you’re looking to keep your lawn healthy after weed treatment, check out our non-toxic biostimulants and fertilizers that make lawn care a breeze.
Ron Henry
Ron Henry is the founder of Golf Course Lawn, which is dedicated to helping homeowners achieve golf course-quality lawns. He holds a certificate in Sports Turfgrass Management from the University of Georgia. With expert knowledge in turf care, fertilization, and weed control, he shares practical tips and product recommendations to create lush, healthy lawns.