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how to get rid of nutsedge in st augustine grass

How to Get Rid of Nutsedge in St Augustine Grass

Nutsedge is persistent and aggressive weed found in lawns. It can be exceedingly difficult to kill, and controlling it might take longer.

You can use ortho nutsedge killer to get rid of nutgrass in your lawn. You can also get rid of nutsedge in St  Augustine grass by digging it out. Natural home remedies such as using vinegar are also effective against nutgrass.

To get rid of nutsedge or control it, you must first understand it and its growth patterns. Here’s what you need to know about how to get rid of Nutsedge in St Augustine grass.

What does nutsedge look like?

Nutsedge has the appearance of St. Augustine grass, but it grows much faster. It is a grass-like perennial weed that prefers damp, poorly drained areas of your lawn. Nutsedge grows faster than grass and can be tough to deal with, especially in summer. 

Nutsedge has a triangular-shaped stem. The leaves are shiny and form a “V” shape with a noticeable center rib. The spiky head is purple or yellow, and the leaves are grasslike.

Purple nutsedge grows in the late summer, while yellow nutsedge grows in the middle of the summer. These weeds are taller than your lawn grass and notoriously difficult to eradicate due to their extensive root systems.

How to Get Rid of Nutsedge in St Augustine Grass

Here are methods that work if you want to do away with nutsedge in St. Augustine grass.

1. Killing Nutsedge using Herbicides

Herbicide treatments are the most effective technique to get rid of this bothersome weed.

There is a variety of herbicide options to choose from. Most nutsedge herbicides contain active compounds such as Halosulfuron and Sulfentrazone. One application should be enough to eliminate it if the infestation is not too bad.

Here’s a table that shows some of the best herbicides to use against nutgrass.

Herbicide nameActive ingredientEffectivenessType
Ortho® Nutsedge Killer
SulfentrazoneEPostemergent
Blindside Herbicide WDG FMC
Metsulfuron 6%, Sulfentrazone 60%FPostemergent
Sedgehammer Herbicide
Halosulfuron-methylFPostemergent
Bonide Sedge Ender
SulfentrazoneFPostemergent
Tenacity Turf Herbicide
MesotrioneFPre and post-emergent

E= Excellent, F= Fair, P= Poor

Many common herbicides will have little or no effect on nutsedge because it’s a sedge. That is why it is critical to seek out products designed specifically to control sedges. Glyphosate can be used to remove isolated patches of nutsedge.

You should note that using other herbicides will also affect the grass growing in your lawn. These selective herbicides(In the table) target only the nutgrass in your lawn. However, make sure you read the herbicide label carefully before using it on your turf.

Also read: Best herbicide for dandelions that won’t harm grass

2. Digging the Nutsedge out

Nutsedge is difficult to control because it develops multiple tubers that give rise to a new plant. The tubers break off in the ground when the weed is plucked out by hand, stimulating new growth.

Therefore, digging around the weed before pulling it out is the best way to ensure you remove all the nutlets. The nutsedge plants will regenerate in the same area if the nutlets and rhizomes are not removed.

You can dig out nutsedge with a spade if there’s a tiny amount in the grass. However, you must be very careful not to leave any roots in the soil since nutsedge will regrow if roots are left behind. 

Dig at least 10 inches into the ground and 8 to 10 inches around the nutgrass patch. This will enable you to remove all the tubers in the area.

Tilling your lawn frequently will remove all the nutsedge tubers from the ground over time, but you should properly clean your equipment after digging out the nutsedge to prevent the tubers and rhizomes from spreading.

The best time to dig out nutsedge is before new tubers are generated in spring.

Also read: Ways to revive dead St Augustine grass

3. Using Vinegar to Kill Nutsedge

Vinegar can help manage weeds. Apply it on a sunny day, just like any other weed killer. You should avoid windy days because wind carries the vinegar to locations you don’t want it in.

Remember that vinegar is weakened by rain, which dilutes its effects, so you might need to check the weather forecast before applying vinegar.

Also read: Will vinegar kill torpedo grass

Vinegar is non-selective thus will harm any grass it comes into contact with. Ensure the vinegar doesn’t land on other plants when sprinkling it on the weeds. Use a brush to paint the vinegar onto the nutsedge if sprinkling is impossible.

Make sure to coat the whole plant well. The acetic acid in the vinegar will cause the leaves to burn and dry out. Wait at least two weeks before spraying again.

When using more concentrated vinegar, make sure to protect your face and skin. Higher concentrations of vinegar can burn skin, injure eyes, and induce bronchitis if inhaled.

Also read: What kills everything but bermuda grass

Controlling Nutsedge

Nutgrass does not do well in shadows, so modifying landscape vegetation might help control the weed. Nutsedge grows well in damp environments with excessive irrigation or leaking sprinklers. Fixing the drainage in your lawn will help limit nutsedge growth.

While pulling out nutsedge is usually not effective, you can get rid of young tubers using this method. If the nutsedge plant still has less than six leaves, you can pull it out by hand. However, mature weeds usually have root tubers buried deep in the soil, so pulling them out might break them off

Nutsedge tubers are planted in topsoil and nursery stock and spread via cultivation and can survive for several years in the soil. Learn to recognize nutsedge to avoid bringing it in on newly purchased St. Augustine. If you mow your lawn at the right height, the grass will crowd out nutsedge and other weeds.

Weeding out nutsedge in St.Augustine grass is not a difficult process, but it requires a lot of patience.

You can either choose the chemical method using herbicides or apply home remedies like vinegar.

Next time you return from your summer vacation and notice nutsedge in your St. Augustine grass, just follow the steps above on how to get rid of nutsedge in St Augustine grass.

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