Is your beautiful St. Augustine grass lawn getting taken over by pesky weeds? It’s a common problem for many homeowners. You want a lush, green carpet, but unwanted invaders keep popping up, ruining the look and health of your grass. Figuring out which weed killer to use can feel like a maze, especially when you need to protect your delicate St. Augustine grass. You might worry about accidentally harming your lawn while trying to get rid of the weeds.
Choosing the wrong product can lead to yellowing, damaged grass, or worse, weeds that just keep coming back. That’s why knowing the right kind of post-emergent herbicide to use is so important. This guide is here to help you sort through the confusion. We’ll break down what you need to know to pick the best weed killer for your St. Augustine grass, so you can get back to enjoying a healthy, weed-free lawn.
Keep reading to discover the most effective post-emergent herbicides that are safe for your St. Augustine grass. We’ll explain how they work and give you tips for using them correctly. Get ready to say goodbye to those unwanted weeds and hello to a perfect lawn!
Our Top 5 Post Emergent Herbicide For St Augustine Grass Recommendations at a Glance
Top 5 Post Emergent Herbicide For St Augustine Grass Detailed Reviews
1. Blindside Herbicide WDG 8 oz. Post Emergent Broadleaf Weed Killer
Rating: 8.5/10
Tired of pesky broadleaf weeds taking over your lawn? The Blindside Herbicide WDG 8 oz. Post Emergent Broadleaf Weed Killer is here to help! This product is designed to tackle those unwanted plants after they’ve already sprouted, making your yard look neat and tidy. It’s a convenient way to keep your grass looking its best.
What We Like:
- It effectively kills a wide range of broadleaf weeds.
- The “WDG” means it’s water-dispersible granules, which are easy to mix and apply.
- It works after the weeds have already grown, so you can see exactly where to treat.
- The 8 oz. size is good for treating a decent-sized area without being too much product.
What Could Be Improved:
- It’s a post-emergent, meaning it won’t prevent weeds from growing in the first place.
- You’ll need to be careful to only spray the weeds and not your desired grass, as it can harm it too.
- The “N/A” for features suggests there might not be many extra bells and whistles, just the core function.
If you’re looking for a straightforward solution to existing broadleaf weeds, Blindside Herbicide WDG is a solid option. Just remember to follow the instructions carefully for the best results.
2. Syngenta Tenacity Herbicide – Pre-Emergent and Post-Emergent Weed Control
Rating: 8.9/10
Tired of weeds taking over your lawn? The Syngenta Tenacity Herbicide is a powerful liquid weed killer that tackles a wide variety of common lawn invaders. It works both before weeds sprout and after they’ve started growing, making it a versatile solution for a healthy, green yard.
What We Like:
- BROAD-SPECTRUM WEED CONTROL: It kills 46 different types of weeds, including tough ones like crabgrass, clover, and dandelions.
- APPLICATIONS AT SEEDING: You can use it when you’re planting new grass or overseeding, which is a big plus.
- SELECTIVE PRE- AND POST-EMERGENT CONTROL: It stops new weeds before they start and kills existing ones without hurting your lawn.
- EASY TO MEASURE AND POUR: The bottle design makes it simple to get the right amount, so no more guessing or messy measuring cups.
- TRUSTED ORIGINAL: This is the original brand with mesotrione, a proven ingredient, and many lawn care pros trust it.
What Could Be Improved:
- LABEL READING: You need to check the label to make sure it’s safe for your specific type of turfgrass.
- CONCENTRATED FORMULA: It’s a liquid that needs to be mixed with water, so you’ll need to do that step yourself.
For lawns that need serious weed help, Syngenta Tenacity offers reliable control. It’s a great option for keeping your grass looking its best throughout the season.
3. Mesotrione Weed Killer Concentrate for New & Existing Lawns 8 oz. (Compare to Tenacity) Post & Pre Emergent Weed Control Liquid Herbicide for Broadleaf Prevent & Crabgrass Killer for Lawns
Rating: 8.7/10
Achieve a beautiful, weed-free lawn with this Mesotrione Weed Killer Concentrate. This powerful liquid herbicide works both before weeds sprout (pre-emergent) and after they appear (post-emergent). It’s designed for both new and existing lawns, making it a versatile choice for any homeowner. Say goodbye to stubborn weeds and hello to a healthier, greener yard.
What We Like:
- Effective weed control: It stops weeds before they start and kills existing ones, including tough ones like crabgrass, dandelions, clover, and yellow nutsedge.
- Easy application: You can spray it easily, ensuring it covers your lawn evenly.
- Preemergent prevention: It helps keep your lawn clear of weeds, especially after spring seeding.
- Long-lasting results: Enjoy protection from weeds for a longer time.
- Trusted formula: This is a reliable product that gives consistent results.
- Great value: You get the same effective Mesotrione formula as other brands, but at a better price. It’s from a USA-based company with a satisfaction guarantee.
What Could Be Improved:
- The label lists many weeds it controls, but it’s always good to double-check if it handles your specific problem weeds.
- While the application is easy, understanding the correct mixing ratio is important for best results.
This weed killer concentrate is a smart choice for anyone wanting a pristine lawn. It offers effective control and great value, making lawn care simpler and more successful.
4. Monterey Grass Getter Bundled with Measuring Spoon – Selective Post Emergent Herbicide – Kills Weedy Grasses
Rating: 8.8/10
Tired of pesky grassy weeds ruining your beautiful flower beds and vegetable gardens? The Monterey Grass Getter, bundled with a handy measuring spoon, is your solution. This powerful post-emergent herbicide targets and eliminates a wide range of unwanted grasses, letting your desirable plants thrive.
What We Like:
- Effectively kills many common grassy weeds like crabgrass, bermudagrass, and johnsongrass.
- Safe to spray directly over your ornamental plants, shrubs, and vegetables, ensuring they are not harmed.
- Works systemically, meaning it travels from the leaves down to the roots for a complete kill.
- The bundle includes a measuring spoon, making it simple to get the right mix.
- Great for use in flower beds, ground covers, and garden areas.
What Could Be Improved:
- Does not control nutsedge (nutgrass), annual bluegrass (poa annua), or broadleaf weeds.
- For best results, it’s recommended to use it with a surfactant/oil concentrate, which is an additional purchase.
- Takes longer to work in cooler temperatures.
- Not for use in your lawn.
Overall, the Monterey Grass Getter is a fantastic tool for keeping your garden beds free of unwanted grasses. Just remember to apply it correctly for the best results.
5. Lawn Synergy Lesco Three-Way Selective Post Emergent Liquid Herbicide (1 Gallon)
Rating: 9.0/10
Tired of pesky broadleaf weeds taking over your lawn? The Lawn Synergy Lesco Three-Way Selective Post Emergent Liquid Herbicide is here to help. This powerful gallon jug offers professional-strength weed control that works fast. It targets and kills most common broadleaf weeds, leaving your lawn looking neat and tidy.
What We Like:
- Fast-Acting Weed Control: You’ll see results quickly as this herbicide goes to work on broadleaf weeds.
- Professional Strength: This isn’t your average weed killer; it’s designed for tough jobs.
- Kills Most Broadleaf Weeds: It effectively tackles a wide range of unwanted plants that can harm your grass.
- Easy to Use: Simply mix and apply according to the instructions for hassle-free application.
What Could Be Improved:
- Selective Application Required: It’s important to only spray on weeds and avoid desirable plants as it is selective.
- Requires Proper Mixing: Following the mixing instructions precisely is key for best results.
For a healthier, weed-free lawn, the Lawn Synergy Lesco Three-Way Selective Post Emergent Liquid Herbicide is a solid choice. It delivers powerful performance and makes weed management straightforward.
The Ultimate Buying Guide: Keeping Your St. Augustine Lawn Weed-Free
Your St. Augustine grass lawn is a beautiful thing. It’s thick, green, and inviting. But weeds can quickly spoil the view. Fortunately, you can fight back with a post-emergent herbicide. This guide will help you choose the best one for your needs.
What is a Post-Emergent Herbicide?
A post-emergent herbicide is sprayed on weeds after they have already sprouted. It works by killing the weeds you see, not preventing them from growing in the first place. This is perfect for tackling existing weed problems in your St. Augustine lawn.
Key Features to Look For
1. Weed Specificity
Some herbicides kill many types of weeds. Others are made for specific weeds. For a St. Augustine lawn, you want a herbicide that targets common lawn weeds like dollarweed, crabgrass, and nutsedge. Always check the product label to see which weeds it controls.
2. St. Augustine Grass Safety
This is the most important feature! Not all herbicides are safe for St. Augustine grass. Some can damage or even kill your lawn. Look for products that specifically state they are safe for St. Augustine grass. This information is usually on the front of the label.
3. Formulation Type
Herbicides come in different forms: liquid concentrates, ready-to-use sprays, and granular forms.
- Liquid concentrates are mixed with water. They are often more cost-effective but require careful measuring.
- Ready-to-use sprays are convenient and don’t need mixing. They are great for small areas or quick spot treatments.
- Granular herbicides are spread on the lawn and watered in. They can be easy to apply evenly.
Choose the formulation that best fits your application method and the size of your lawn.
4. Active Ingredients
The active ingredients are what actually kill the weeds. Common active ingredients found in safe St. Augustine herbicides include 2,4-D, MCPP (mecoprop), and dicamba. Sometimes, these are combined. Always read the “Ingredients” section on the label.
Important Materials to Consider
When buying a post-emergent herbicide, you’ll also need a few other things for safe and effective application:
- A Sprayer: Whether it’s a backpack sprayer, a hose-end sprayer, or a simple trigger sprayer, you need a way to apply the herbicide evenly.
- Protective Gear: Gloves, long sleeves, long pants, and eye protection are essential to protect yourself from the chemicals.
- Water: If you’re using a concentrate, you’ll need water to mix it.
Factors That Improve or Reduce Quality
Factors That Improve Quality:
- Proven Effectiveness: Look for brands with good reviews and a history of killing the weeds you have.
- Selective Action: A high-quality herbicide will kill weeds without harming your St. Augustine grass.
- Ease of Use: Clear instructions and a user-friendly formulation make application much simpler.
Factors That Reduce Quality:
- Non-Selective Herbicides: These kill all plants, including your grass.
- Incorrect Application: Applying too much or at the wrong time can damage your lawn.
- Old or Expired Products: These may not be as effective.
User Experience and Use Cases
Most users find post-emergent herbicides to be very effective when used correctly. They are ideal for homeowners who want to maintain a beautiful, weed-free lawn. Common use cases include:
- Spot treating individual weeds as they appear.
- Treating larger areas of the lawn that have a significant weed problem.
- Preventing weeds from spreading further.
Remember to always follow the instructions on the product label for the best results and to protect your lawn.
Frequently Asked Questions (FAQ)
Q1: Can I use any weed killer on my St. Augustine grass?
A1: No, you must use a herbicide that is specifically labeled as safe for St. Augustine grass. Many common weed killers can harm or kill it.
Q2: When is the best time to apply a post-emergent herbicide?
A2: The best time is when weeds are young and actively growing. Avoid applying when temperatures are very high, or when rain is expected soon after application.
Q3: How do I know if the herbicide is safe for my lawn?
A3: Always check the product label. It will clearly state which types of grass the herbicide is safe to use on.
Q4: What if I see weeds after I’ve already treated my lawn?
A4: Some weeds may require a second application. Check the product label for reapplication instructions and wait the recommended time between treatments.
Q5: Can I water my lawn after applying the herbicide?
A5: This depends on the product. Some require watering to activate, while others are best left to dry on the leaves. Always read the label instructions.
Q6: What are the most common weeds in St. Augustine lawns?
A6: Common weeds include dollarweed, crabgrass, nutsedge, and goosegrass. Look for herbicides that list these on their target weed list.
Q7: Do I need to wear protective gear?
A7: Yes, it is always recommended to wear gloves, long sleeves, long pants, and eye protection when applying any herbicide.
Q8: How long does it take for the weeds to die?
A8: It can take several days to a couple of weeks for weeds to completely die after treatment, depending on the weed and the product used.
Q9: Can I use a post-emergent herbicide when it’s hot outside?
A9: It’s generally best to avoid applying herbicides when temperatures are above 85-90°F (29-32°C) as this can increase the risk of damaging your St. Augustine grass.
Q10: How do I dispose of leftover herbicide?
A10: Never pour leftover herbicide down the drain or into waterways. Check your local regulations for proper disposal methods, or contact your local waste management authority.
In conclusion, every product has unique features and benefits. We hope this review helps you decide if it meets your needs. An informed choice ensures the best experience.
If you have any questions or feedback, please share them in the comments. Your input helps everyone. Thank you for reading.
I’m the recipe developer and food photographer behind Air Fryer at Tiffany’s. I’m also a wife, mom to two adventurous little boys, registered nurse, and live in the great Midwest. Join me as I show you new ways to use your air fryer that you never knew possible.