Will Atrazine Kill Bermuda Grass?

While some use the hearty Bermuda grass for their lawns, many others see it as a weed. It’s a perennial that can tolerate bouts of heat and drought exceptionally well, making it perfect for hot climates.

That is, however, only a good thing if you’re in the group that likes the resilient grass. If you view it as a weed, its heartiness and tolerance may be an annoyance to you, in which case you’ll be looking for a way to rid it from your lawn to let your grass of choice take center stage.

In this article, we’ll go over atrazine—a popular herbicide—and its effect on Bermuda grass.

Will Atrazine Kill Bermuda Grass?

Although a hardy plant, atrazine can kill Bermuda grass if applied at the right time. When used in spring, either right before the grass has emerged or shortly after it has sprouted, the herbicide is an effective killer of Bermuda grass.

It’s important not to wait too long after the grass has sprouted, as it will only become more resilient and therefore harder to kill. Once the grass is strongly-established later into the summer, atrazine will be mostly ineffective.

Keep in mind that spraying atrazine on dormant Bermuda grass in the winter months will also have no effect on it; atrazine does nothing to dormant grasses. It’s best to apply the herbicide when temperatures are in the mid-range, as both too hot and too cold of temperates can lower its effectiveness.

While applying atrazine does require some planning in order to properly work, it is an excellent option for getting rid of unwanted Bermuda grass.

Atrazine and its Effect on Other Grasses

Bermuda grass isn’t the only kind of grass that atrazine kills. In fact, only two common species of grass are not harmed by atrazine, which are St. Augustine and Centipede grasses.

While this does mean that atrazine is a versatile and effective herbicide for many unwanted plants, it also means that it’ll kill most other plants it comes in contact with too, including the plants or grass you planted intentionally.

So unless your grass is comprised of either St. Augustine or Centipede grass, you’ll want to choose another herbicide, or you’ll kill your entire lawn.

How Long Will it Take Atrazine to Kill Bermuda Grass?

Atrazine is a slow-acting herbicide, needing time to break down plant systems. Allow between four and six weeks after you apply atrazine to see results, as they will not happen right away.

Signs that the herbicide is working are the Bermuda leaf blades beginning to yellow at the edges, fewer runners existing from Bermuda patches, and little to no new sprouts.

What If Atrazine Isn’t Properly Killing Bermuda Grass?

Bermuda grass is incredibly tough and resilient, making it somewhat challenging to get rid of once it invades your lawn. If applied correctly, atrazine will at the very least halt the spread of Bermuda grass, although it is possible that the existing grass will remain.

If this is the case for you, there are other options out there to get your yard back to the condition you want it to be in. Ornamec 170 is a great option, as it’ll kill Bermuda grass while still being safe for most other types of grasses, including whatever your desired choice is.

It’s still always best to do a quick check to see the relation of your herbicide to your grass before doing anything—you don’t want to end up wrecking your entire lawn when you only meant to get rid of a few intruders.

Roundup or another glyphosate-based weed killer is another option for killing Bermuda grass. However, this kind of herbicide is best used as a spot treatment for pesky weeds, as it’ll also kill all other plants it comes in contact with.

It’ll wipe out your unwanted Bermuda grass, but unfortunately, it’ll do the same to your wanted grass.

How Long Does Atrazine Last After Initial Application?

Atrazine can remain active on your lawn for up to six weeks. During this time, it’ll kill Bermuda grass below the ground as it begins to germinate, as well as the grass that begins to sprout.

This is good news if you’re looking to get rid of Bermuda grass, but bad news if you plan to seed your lawn with any other grass than Centipede or St. Augustine.

The atrazine will still be active in the soil and will kill any sprouts that begin to grow, so keep that in mind if you’re planning to seed your lawn at any point during the six-week period post atrazine application.

The same rule of thumb applies to any garden beds or areas where you might plant anything that isn’t Centipede or St. Augustine grass.

Atrazine and the Environment

Atrazine is applied topically to lawns, although unfortunately, it doesn’t stay there forever. The runoff of atrazine often ends up in reservoirs and, therefore, in the tap water of the surrounding area, which can pose a risk to the residents.

If found in greater amounts than the health standard, it can cause health risks such as low blood pressure, muscle spasms, and damage to the adrenal glands. With long-term exposure, there could be a risk of cardiovascular damage, retinal and muscle degeneration, and possibly cancer.

Those at greatest risk are the people who are regularly involved in the production and application of atrazine, so while the general public can be exposed over time, they might not experience the same level of health risks.

Not only does atrazine have an effect on humans, but it also, unfortunately, has an impact on the ecosystem and wildlife as well. Just like it does to the plants in your yard, it stops or slows the growth of flora and fauna in the wild as well.

This understandably poses a considerable risk; upsetting a delicate natural ecosystem can throw things off in a far more detrimental way than you may realize.

Animals can also be impacted by atrazine, fish, and amphibians especially. Enough exposure in the water they live in can compromise their growth, immune function, behavior, and gonadal development.

A biologist at UC Berkeley has found that atrazine in male frogs can cause them to become functionally female, as the herbicide has a drastic effect on hormones. This alters the standard reproduction rate of frogs, which can, in turn, throw the whole ecosystem out of balance.

For many understandable reasons and varying country to country, atrazine has stringent laws and is even banned in some countries. The United States by far has the least restrictive laws on herbicide, which has proven to cause problems over the years. It’s always a good idea to do your research before purchasing any kind of herbicide or pesticide.

What Exactly is Atrazine?

Atrazine is a man-made herbicide, which was registered for use for the first time in 1958. It’s apart of the triazine class—a group of herbicides that contain nitrogen.

Its use is to prevent the growth of broadleaf weeds in crops such as sugar cane and corn, as well as places like residential lawns and golf courses.

As one of the most widely used herbicides in the United States and Australia, atrazine is no stranger to the people in the world of herbicides. As of 2014, 76 million pounds of it is applied each year in the United States.

What Exactly is Bermuda Grass?

Native to subtropical and tropical countries all around the world, Bermuda grass is a perennial warm-season plant. Documents that date back to 1807 show that it was already one of the most widely used grasses in America’s Southern parts.

Being a perennial, it comes back every year starting around late spring and flourishes all the way until the late summer months.

Though it is a hearty grass that can withstand and even thrive in hot temperatures, Bermuda grass can be more sensitive to cold temperatures than some of the other grasses.

Bermuda grass has the fastest growth rate out of any of the warm-season grasses, which can be both a pro and a con depending on how you look at it. Since it grows so fast, it requires more frequent upkeep.

Although on the flip side, it can endure more heavy usage, which makes it great for golf course turfs and athletic fields.


If you’re looking for an effective herbicide for the pesky Bermuda grass that keeps spreading throughout your perfectly manicured yard, atrazine may be the right choice for you.

Not only halting the growth of the unwanted grass, atrazine will also kill any new sprouts before they even manage to pop up.

While a popular and effective herbicide for Bermuda grass, atrazine is also excellent at getting rid of most other grasses and plants too, so be sure to do your research to ensure that you’ll only be getting rid of the unwanted weeds rather than your entire lawn.

If your yard is comprised of St. Augustine or Centipede grass, atrazine will do a perfect job at killing off the Bermuda grass, all while still keeping the rest of your lawn healthy and green.

Also read

Will St. Augustine Take Over Bermuda Grass?

Does Bermuda Grass grow in Shade: How shade Tolerant is it?

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