Best Weed Killer for St Augustine Grass: Top Picks for a Lush Lawn

St. Augustine grass is a favored warm-season grass in the southern U.S due to its tolerance to heat, humidity, and shade. Nevertheless, a key difficulty in preserving a St. Augustine lawn is weed control. Weeds can quickly infest a lawn, battling with the grass over water and nutrients, which could result in a chaotic and unhealthy lawn.

The most effective way to control weeds in St. Augustine grass is by using a weed killer specifically formulated for this grass type. The right weed killer can eliminate weeds without harming the grass, leaving you with a beautiful and healthy lawn.

When choosing a weed killer for St. Augustine grass, it’s essential to pay attention to the active ingredients. Some weed killers contain chemicals that can harm St. Augustine grass, so it’s crucial to choose a product that is safe for this grass type. It’s also important to consider the type of weeds you’re dealing with and choose a product that is effective against those specific weeds.

We spent hours researching and testing various weed killers to identify the best options for controlling weeds in St. Augustine grass. In the following sections, we’ll share our top picks and provide detailed information on each product’s features and benefits.

Best Weed Killers for St. Augustine Grass

We know that maintaining a healthy and lush St. Augustine grass lawn requires a lot of effort. One of the most challenging tasks is keeping weeds at bay. That’s why we’ve researched and tested various weed killers to provide you with a list of the best options available. Our roundup includes weed killers that are safe for St. Augustine grass and effective in controlling weeds. Read on to find the perfect solution to keep your lawn weed-free.

1. Ortho WeedClear Weed Killer for Lawns Ready-To-Spray

We highly recommend purchasing Ortho WeedClear Weed Killer for Lawns Ready-To-Spray for those looking for a powerful weed killer that won’t harm their lawn.

We were impressed with the effectiveness of Ortho WeedClear Weed Killer for Lawns Ready-To-Spray. It killed a wide variety of weeds quickly and effectively, without harming our lawn. We appreciated the easy-to-use spray nozzle that allowed us to target specific areas.

We did find that some stubborn weeds required multiple treatments to fully eradicate, but overall we were pleased with the results. It’s important to use this product as directed for best results, and to apply when weeds are small and actively growing in the spring or fall.

Overall, we highly recommend Ortho WeedClear Weed Killer for Lawns Ready-To-Spray for those looking for a reliable and effective weed killer that won’t harm their lawn.

2. Southern Ag 006130 Atrazine St. Augustine Weed Killer 32oz Specialty Herbicide, Light Tan

If you’re looking for an effective weed killer for St. Augustine and Centipede grasses, the Southern Ag 006130 Atrazine St. Augustine Weed Killer might be worth considering.

We’ve used this weed killer on our St. Augustine lawn and found it to be effective in controlling weeds. One quart of the product treated a large area and we saw a noticeable reduction in the number of weeds within a few days.

One of the things we liked about this product is that it not only controls broadleaf weeds but also many common grassy weeds. It also provides suppression of crabgrass, which is a common problem in many lawns.

However, it’s important to note that this product is not recommended for use with hose-end sprayers and you need to spray accurately to obtain the indicated coverage without overlap. We also found that best results were obtained by applying the product in early spring.

Overall, if you’re looking for an effective weed killer for your St. Augustine or Centipede grass lawn, the Southern Ag 006130 Atrazine St. Augustine Weed Killer is definitely worth considering.

3. Southern Ag Atrazine St. Augustine Grass Weed Killer

If you’re looking for an effective weed killer for St. Augustine grass, Southern Ag Atrazine St. Augustine Grass Weed Killer is a great option to consider.

We recently used Southern Ag Atrazine St. Augustine Grass Weed Killer in our yard and were pleased with the results. The product effectively killed many broadleaf weeds, including crabgrass, and provided suppression of crabgrass.

One thing to keep in mind is that the product is not recommended for use with hose-end sprayers, so you’ll need to use a different type of sprayer. Additionally, it’s important to spray accurately to obtain the indicated coverage and avoid overlapping.

Overall, we found Southern Ag Atrazine St. Augustine Grass Weed Killer to be an effective solution for controlling weeds in St. Augustine grass. While it may take a few weeks to see results, the product is easy to apply and provides good coverage.

4. Spectracide Weed Stop For Lawns For St. Augustine & Centipede Lawns Concentrate

If you’re looking for an effective weed killer that won’t harm your St. Augustine or centipede grass, Spectracide Weed Stop For Lawns For St. Augustine & Centipede Lawns Concentrate is worth considering.

We used Spectracide Weed Stop For Lawns For St. Augustine & Centipede Lawns Concentrate on our St. Augustine lawn and were pleased with the results. We sprayed the lawn until it was wet to control weeds, and it did not harm the grass. We also noticed a significant reduction in the amount of weeds after about two weeks.

While this product is easy to use, it does not work overnight, so you should not expect to go out the next day and see dying weeds. Also, do not apply when daytime temperatures are above 90 degrees because injury to your lawn can occur.

Overall, if you’re looking for a weed killer that won’t harm your St. Augustine or centipede grass, Spectracide Weed Stop For Lawns For St. Augustine & Centipede Lawns Concentrate is a good option to consider.

5. Fertilome St. Augustine Weed & Feed 15-0-4

If you’re looking for a weed killer that also helps fertilize your St. Augustine grass, then Fertilome St. Augustine Weed & Feed 15-0-4 is worth considering.

We used Fertilome St. Augustine Weed & Feed 15-0-4 in early spring and noticed a significant reduction in the number of weeds in our St. Augustine grass. The fertilizer mix also helped improve the overall health of our lawn throughout the season.

One thing to keep in mind is that this product should not be used on Bermuda Grasses or any other type of Northern grass. Additionally, the coverage varies depending on the size of your lawn, so be sure to check the label for application instructions.

Overall, we would recommend Fertilome St. Augustine Weed & Feed 15-0-4 to anyone looking for a weed killer and fertilizer combo for their St. Augustine grass.

6. Ortho Weed B Gon Weed Killer for St. Augustinegrass Ready-To-Spray

If you’re looking for a reliable weed killer for your St. Augustinegrass lawn, Ortho Weed B Gon is a great option to consider.

We recently tried Ortho Weed B Gon on our St. Augustinegrass lawn and were impressed with the results. After just one application, we noticed a significant reduction in the number of weeds in our lawn. We appreciated that it didn’t harm our grass and was rain-proof in just one hour, so we didn’t have to worry about the weather affecting its effectiveness.

However, we did have to apply it a few times to get rid of some of the tougher weeds, which was a bit of a downside. We also noticed that the spray nozzle wasn’t the most durable and had some issues with it during application. Additionally, we made sure to follow the instructions carefully as it can be harmful to pets and wildlife if not used as directed.

Overall, we would recommend Ortho Weed B Gon for anyone looking for a reliable weed killer for their St. Augustinegrass lawn. Just make sure to follow the instructions carefully and be prepared to apply it a few times for tougher weeds.

7. Hi-Yield Atrazine Weed Killer

If you’re looking for a weed killer that can control Henbit, Dollarweed, Chickweed, Clover, Sandspur, and others listed on the label, Hi-Yield Atrazine Weed Killer is a great option.

We’ve used Hi-Yield Atrazine Weed Killer before and it did what the chemical is supposed to do. It really kills the weeds, not the St. Augustine grass. We didn’t see results until 7 to 10 days after application, but it was worth the wait.

One thing we didn’t like about this weed killer is that it’s hard to measure out. You’ll need to pour it into a measuring cup, as you cannot use the markings on the side of the bottle. Some users reported that it didn’t work, but we didn’t have this issue.

In conclusion, if you’re looking for a weed killer that can control tough weeds in St. Augustine and Centipedegrass, Hi-Yield Atrazine Weed Killer is a great option. Just be aware that it takes a bit of time to see results and it can be hard to measure out.

8. BioAdvanced Season Long Lawn Weed Killer + Preventer for Southern Lawns

If you’re looking for a weed and feed that does more, BioAdvanced Season Long Lawn Weed Killer + Preventer for Southern Lawns is definitely worth considering. It’s specifically formulated for use on Southern lawns, including all varieties of St. Augustinegrass, including Floratam. This product kills listed broadleaf weeds, including dandelion, clover, and dollarweed, and it prevents listed broadleaf and grassy weeds plus crabgrass for up to 6 months.

In our experience, BioAdvanced Season Long Lawn Weed Killer + Preventer for Southern Lawns is effective at killing and preventing weeds. We appreciated that it’s formulated specifically for Southern lawns, which can be tricky to manage. The fact that it won’t harm your lawn is a big plus, and we found that it did indeed provide season-long control of weeds.

That being said, some users have reported issues with clumping, so be sure to follow the instructions carefully to avoid this. Additionally, the granules can cause throat irritation if inhaled, so we recommend wearing protective gear during application. Finally, it’s important to note that it can take a few weeks to see results, so be patient.

Overall, we would recommend BioAdvanced Season Long Lawn Weed Killer + Preventer for Southern Lawns to anyone looking for a weed and feed that’s specifically formulated for Southern lawns and provides season-long control of weeds.

9. Image Weed Killer Concentrate 32 Oz.

We highly recommend purchasing this weed killer if you’re looking for a reliable solution to control broadleaf and grassy weed in St. Augustine and centipede grasses.

We’ve used Image Weed Killer Concentrate 32 Oz. for our St. Augustine grass and centipede grass turfs and were impressed with its effectiveness in controlling various weeds. It’s easy to use, and we didn’t need to mix it with water, making the application process hassle-free. After a few hours of application, it became rainproof, so we didn’t have to worry about it washing away.

The only downside we noticed was that it takes a few days to a week to see visible results. For heavily infested areas, we had to apply it multiple times. Additionally, it may cause temporary yellowing of grass blades, but it eventually recovers.

Overall, Image Weed Killer Concentrate 32 Oz. is a great product for controlling broadleaf and grassy weed in St. Augustine and centipede grasses. We highly recommend it to anyone looking for a reliable solution to their weed problems.

10. BioAdvanced 3-In-1 Weed and Feed for Southern Lawns

If you’re looking for a weed and feed that does more, the BioAdvanced 3-In-1 Weed and Feed for Southern Lawns is worth considering. It not only fights to kill weeds, but also strengthens your lawn and prevents new weeds from appearing.

We recently used this product on our St. Augustinegrass lawn and were pleased with the results. The granules were easy to apply with our broadcast spreader and we noticed a significant reduction in weeds within a few weeks. Our lawn also looked greener and healthier overall.

One of the biggest advantages of this product is the long-lasting protection it provides. With just one application, we were able to prevent new weeds from appearing for up to 6 months. This saved us time and money compared to using multiple products throughout the season.

It’s important to note that this product is specifically formulated for Southern lawns and should not be used on Northern turf. We also found that heavily weeded areas may require multiple applications for best results.

Overall, we would recommend the BioAdvanced 3-In-1 Weed and Feed for Southern Lawns to anyone looking for a convenient and effective solution to weed control and lawn care.

11. Agralawn Crabgrass Killer

If you’re looking for a safe and effective weed killer for St. Augustine grass, you might want to consider Agralawn Crabgrass Killer.

We recently tried Agralawn Crabgrass Killer on our St. Augustine grass and were pleased with the results. The product is easy to apply and doesn’t require any special equipment. We simply sprinkled the powder over the crabgrass and made sure it got on the leaves.

One of the things we liked about this product is that it’s safe to use on several types of grass, including St. Augustine, which can be sensitive to some weed killers. We didn’t notice any yellowing or damage to our grass after using Agralawn Crabgrass Killer.

Another benefit of this product is that it’s exempt from EPA registration under the Federal Insecticide, Fungicide and Rodenticide Act, Section 25(b) rule. This means that it’s made from natural ingredients and is considered safer for the environment than some other weed killers.

The only downside we noticed is that the coverage area is limited to 100-200 square feet of target weeds. This might not be enough for larger lawns or areas with extensive weed growth. Additionally, some customers report mixed results with killing crabgrass, so it’s important to follow the instructions carefully and apply the product as directed.

Overall, we would recommend Agralawn Crabgrass Killer for anyone looking for a safe and effective weed killer for St. Augustine grass. Just be sure to apply it carefully and follow the instructions closely to avoid any damage to your lawn.

Buying Guide

When it comes to choosing the best weed killer for St. Augustine grass, there are a few factors to consider. Here are some features to look for when selecting a product:

Type of Weed Killer

There are two main types of weed killers: selective and non-selective. Selective weed killers only target specific types of weeds and won’t harm your St. Augustine grass. Non-selective weed killers, on the other hand, will kill any plant they come into contact with, including your grass. Make sure to choose a selective weed killer that is labeled safe for use on St. Augustine grass.

Active Ingredients

Different weed killers contain different active ingredients, each with their own strengths and weaknesses. Some common active ingredients in weed killers include glyphosate, 2,4-D, and dicamba. Research the active ingredients in the products you are considering to determine which one is best for your needs.

Application Method

Weed killers come in various application methods, such as sprays, granules, and concentrates. Consider which method will be easiest for you to apply and which will provide the most effective coverage for your lawn.

Coverage Area

Make sure to choose a weed killer that is appropriate for the size of your lawn. Some products are designed for smaller areas, while others are meant for larger lawns or even commercial use. Check the coverage area listed on the product label to ensure it will meet your needs.

Safety Precautions

Always read the label and follow all safety precautions when using any weed killer product. Some products may require protective gear, such as gloves or a mask, while others may have specific instructions for use around children or pets.

By considering these factors, you can choose the best weed killer for your St. Augustine grass and keep your lawn looking healthy and weed-free.

Frequently Asked Questions

How do we safely remove weeds from our St. Augustine grass without harming the grass?

When removing weeds from St. Augustine grass, it is important to use a selective weed killer that will target the weeds without harming the grass. We recommend using a spot treatment with a herbicide that contains 2,4-D, dicamba, and MCPP. Be sure to follow the instructions carefully and avoid spraying on windy days to prevent drift onto desirable plants.

What is the best granular weed killer for St. Augustine grass?

For best results, we recommend using a granular weed killer that contains atrazine. This herbicide is effective in controlling many broadleaf and grassy weeds in St. Augustine grass. Be sure to follow the instructions on the label carefully and apply at the recommended rates.

What is the most effective liquid weed and feed for St. Augustine grass?

When it comes to liquid weed and feed products, we recommend using a product that contains atrazine and 2,4-D. These ingredients are effective in controlling a wide range of weeds in St. Augustine grass while providing essential nutrients to the grass.

Is Atrazine an effective weed killer for St. Augustine grass?

Yes, atrazine is an effective weed killer for St. Augustine grass. It is a selective herbicide that targets a wide range of broadleaf and grassy weeds while leaving the grass unharmed. However, it is important to follow the instructions on the label carefully and avoid over-application.

When is the best time to apply weed killer to St. Augustine grass?

The best time to apply weed killer to St. Augustine grass is during the growing season when the weeds are actively growing. This is typically in the spring and fall. Avoid applying weed killer during the hot summer months when the grass is under stress.

Can we use weed and feed on our St. Augustine grass lawn?

Yes, you can use weed and feed on your St. Augustine grass lawn. However, it is important to choose a product that is specifically formulated for St. Augustine grass and follow the instructions on the label carefully. Over-application can damage the grass and under-application may not provide effective weed control.