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Does Roundup Kill Nutsedge Grass?

Is your lawn filled with pesky nutsedge grass? Are you wondering whether Roundup is the key to killing this pervasive weed? If so, we got you! We did the research to find out whether Roundup can successfully kill nutsedge.

Roundup is an excellent chemical to use for getting rid of nutsedge, and it's one of the most recommended chemicals by experts. Roundup can last a long time in the soil, protecting it from pesky weeds like nutsedge.

You might wonder if it's better to take preventive measures than to use chemicals like Roundup, so in this post, you'll find a guide to preventing nutsedge from growing in your yard. We also included other ways to get rid of nutsedge. If you want to learn more, read on!

Can Roundup Kill Nutsedge Grass?

Nutsedge, also commonly referred to as nutgrass, is a perennial weed that grows at a faster rate than actual grass. This is because nutgrass reproduces seeds that quickly spread throughout the grass and grow quickly.

Roundup is the hero of this post. It's an effective chemical that can kill weeds like nutsedge. The chemical in Roundup, glyphosate, is one of the strongest herbicides for killing weeds.

To kill nutgrass effectively, you need to know how. Ideally, you should apply herbicide by spraying it throughout the affected area. It should also be done during the driest, hottest hour of the day.

Identifying Nutsedge Growth On Your Lawn

Green leaves of herbal Cyperus strigosus or false nutsedge or straw-colored flatsedge on a green meadow

It may take up to two applications of Roundup to effectively kill the weeds, but this largely depends upon the kind of nutgrass you have.

There are two types. Yellow nutgrass, which produces umbrella-shaped flowers, prefers a cold and moist environment. You'll likely need more than two applications to kill this type of nutgrass.

Purple nutgrass, which is dark green with purple seedheads, is more heat tolerant. This type of nutgrass can be especially difficult to get rid of.

But of course, spray and observe. If you can see that the weeds are still thriving, it's okay to do another round.

Other differences between the two types are height. Yellow nutsedge is taller at about 12 to 16 inches. Purple nutsedge reaches 6 inches at full maturity.

To know whether you have a nutsedge problem, inspect the grass. Look for spots and any strange patterns in the grass. If you see one, look closer at the grass itself. Normal grass stems have two leaves in one shoot.

Nutsedge, on the other hand, has three. If you're unsure, you can pluck it and check the stem.

If it's round and hollow, that's regular grass. Nutsedge will be solid and triangular in shape. With the key identifiers in mind, you should be able to spray Roundup.

Difference Between Roundup and Roundup For Lawns

RoundUp weed killer on a store shelf

While Roundup can effectively kill nutsedge, it's only safe to use on your lawn if no turf or other plants are present in the soil. This is because Roundup contains a strong chemical that may destroy your lawn.

Roundup has an active ingredient, galled glyphosate, which can get rid of nutsedge and other weeds as well as all of the plants on your lawn. It's nonselective, which is why it's only recommended for use on an empty lawn.

Roundup For Lawns, however, is different. It's formulated as a selective herbicide that only kills weeds like nutsedge and not the rest of the lawn. Unlike plain Roundup, Roundup For Lawn doesn't contain glyphosate. But how does it work?

Well, Roundup For Lawns has other active ingredients as an alternative to glyphosate. These are bentazon, halosulfuron, sulfentrazone, imazaquin and many more.

These ingredients work on many weeds and do not affect your turf. Do note that just because a brand claims to be Roundup For Lawn or Roundup does not guarantee your turf's safety.

Make sure to look at the label and read the ingredients. Find the ingredients mentioned in this section. You should use a product that will suit your needs.

Check out this Roundup on Amazon

For your reference, here's how each ingredient works in Round Up For Lawn:

Bentazon is excellent for use on centipede grass, bermudagrass, fescue, Augustine grass, and zoysiagrass. You should only use this chemical on mature turf. Make sure the turf hasn't been in contact with water for eight hours to ensure its effectiveness.

Halosulfuron works well in getting rid of both yellow and purple nutsedge. This chemical must be mixed with a gallon of water before treating the turf.

Imazaquin, like bentazon, works with the same grass types except for fescue. After treatment, you should irrigate your lawn so the chemicals will wash out from the plants.

Sulfentrazone works rapidly on weeds. You'll only need two coats of this chemical.

Keeping Your Garden Nutsedge-Free

Cyperus rotundus (coco-grass, Java grass, nut grass, purple nut sedge, purple nutsedge, red nut sedge, Khmer kravanh chruk, rumput teki) with natural background. Cyperus rotundus is a perennial plant., Does Roundup Kill Nutsedge Grass

There's nothing worse than seeing weeds invading your healthy lawn. Although Roundup is a potent herbicide against weeds, it's not a preventive measure and is best used when there is already growth of nutsedge. 

Roundup will halt the growth of weeds like nutsedge but has the potential to kill your garden plants.

The key is maintaining your lawn. This will also be helpful if you're trying to keep your garden chemical-free. Here are some steps aside from using Roundup for keeping your garden nutsedge-free. 

1. Pull The Weeds Every Two Weeks

Pulling weeds before they can reproduce is one of the best ways to decrease their population and eventually get rid of them. As for nutsedge, you should pull them before they can yield more than three leaves.

By doing so, you'll also remove the tubers, which are stuck in the ground and responsible for reproducing nutsedge. Pulling the weeds will be critical to their reproduction.

2. Use Liquid Horticultural Molasses

Horticultural molasses is one way to treat your lawn. Mix a quarter to half a cup of molasses with a gallon of water and spray your lawn with the mixture.

Do at least 2-3 rounds of consistent spraying for best results.

Check out this horticultural molasses on Amazon

3. Avoid Excessive Watering

Yellow Nutsedge aka Cyperus esculentus sedge family is a widespread weed found along water edges and wet areas of lawns that can overtake St. Augustine and Bermuda grass yards areas in South Florida

Weeds like nutsedge love moist soil, so avoid excessive watering. If you have plants nearby that are affected by nutsedge, reduce the water intake or, even better, add an irrigation system.

Find better ways to make your soil more well-draining while plucking all the weeds.

4. Use A Weed Barrier

Weed barriers work to prevent the growth of weeds in your lawn or garden. This barrier is either made of plastic or woven fiber.

The barrier works when the weeds are still young, as they won't get through the fibers, killing them in the process.

Check out this fabric barrier on Amazon

Natural Alternatives To Nutsedge Control

Cyperus rotundus Weeds are narrow and weeds are difficult to control when it grows to a bouquet of reddish brown to dark brown.

You might not know it, but sugar is an effective yet natural way to get rid of nutsedge in your yard. Using it is easy. You'll only need sugar and water.

First, mist your lawn with water—just enough to get it wet. This step is necessary for the sugar to cling to the grass.

Then spread the sugar. Take a small amount and spread it evenly across your yard. Lightly mist your lawn again. Take note of the word "lightly." You don't want to dissolve the sugar in the process.

Use this method during early spring. This way, you can quickly get rid of young nutsedge.

The next method is for especially stubborn nutsedge. It's more of a mechanical method for removing nutsedge from your lawn. 

It's already been established that you need to get to the tubers to stop the weeds from reproducing. That said, this method takes that advice to a whole new level. This method works only if you have a bare lawn or are willing to sacrifice your turf.

You'll need to dig into your lawn to control the growth of nutsedge and eventually kill it. You will need to dig about 10 inches deep into the ground for this task to be successful. Just note that trowels will offer little help in this method.

In Conclusion

Roundup kills nutsedge, or nutgrass, to the point that it can also kill the rest of your lawn! If you're using a Roundup product, be sure to check the ingredients to avoid accidentally damaging your lawn.

Note that there are many other ways to keep your garden weed-free. You just need to be patient with it. You can't use herbicide each time there's nutgrass poking out of your lawn!

Made it this far? Check out these helpful related garden articles below!

How Far Does Roundup Spread?

When Is It Too Cold To Spray Herbicide?