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How To Get Rid Of Water Grass? 4 Amazing Tips!

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The water grass, or Paspalum dilatatum, is a tall perennial that commonly infests lawns, fruits and vegetables. It is a warm-season grass that can reach heights over three feet.

The smooth leaves on these invasive species have long blades which droop down when wet – giving them their name “water.”

There are several effective control methods that you can use to eradicate tufts of water grass. It is important to maintain your lawn by keeping it away from the water grass to get the best possible outcome.

Healthy, dense turf will resist weed invasions and give you years of enjoyment from playing on it with family members or friends! So read this article to know how to get rid of water grass.

How To Get Rid Of Water Grass
Water Grass via Wikimedia

Water Grass Types And Their Control

Water grasses is the term used for weeds by many people. They’re all plants that grow in wetter environments. Some examples of common water-type weeds include rushlike brown.

The few most common water types of grass include quackgrass, tall fescue, yellow nutsedge (​Cyperus esculentus​), nimblewill and crabgrass.

The best way to get rid of pesky weeds is by learning what types they are and how we can kill them. Let’s look at the detail of a few watergrass types.

1. Quackgrass (Elymus repens)

Quackgrass is a dreaded weed for its ability to infest lawns and flowerbeds with ease. It’s allelopathic, meaning it releases chemicals to inhibit the growth of anything else in its proximity. Its ashy, blue-green color with white fleshy rhizomes makes its patches stand out in your lawn.


The best way to avoid quackgrass is by planting a healthy lawn. Soil disturbance near its patches can assist in the spread of this pesky weed, and tillage will only make it worse.

When establishing new turf swards that have had previous issues, make sure to lay sod instead of seeding. It is because the rhizomes will find it difficult to take their place.

2. Tall Fescue (Festuca arundinacea)

Festuca arundinacea How To Get Rid Of Water Grass
Festuca arundinacea via Wikimedia

There are two types of tall fescue. One is the desirable type which is usually improved cultivars. At the same time, other is wide-bladed wild/forage species that can be problematic for your primary blade grasses like grayscale or blond ryegrass.

The desirable one is the improved variety of this grass which its finer blades and drought-tolerant quality can identify.

The one which is not recommended and the older form of this turf has a wider blade. Kentucky 31 (KY-31) is an example of this forage-type variety.


If there are few patches of foliage type tall fescue in your lawn, then the best option is to cut it with your gardening shears. Make sure to stem it out from the soil, and don’t forget to replace those empty places with desirable turf species.

If tall fescue grass is common in any area and its patches are spread all around, controlling it with chemicals would be quite easy. A nonselective herbicide such as glyphosate would work well because it’s easy for weeds but doesn’t harm grasses or other crops nearby.

3. Yellow Nutsedge (Cyperus esculentus)

The yellow nutsedge, nutgrass or water-plant is a pesky weed found throughout North America. It has solid, triangular-shaped stems and the leaves are prominent mid-rib arranged in threes. The color of leaves varies from light green to yellow with a shiny look.

This grass mostly grows in areas where the soil is compact for a long time from over-watering or poor irrigation drainage.


Yellow nutsedge is difficult to control that may need to be treated multiple times with herbicide. The best way of its cultural control is an aggressive dense plantation that can outcompete these invading weeds.

Other practices to get rid of this watergrass weed are deep and occasional watering, increased mowing height and frequent aeration to treat soil compaction.

4. Crabgrass

Crabgrass is a tough, pesky weed with many stems. It grows low to the ground and has an upright growth habit that helps it flourish in any environment.

This warm-season grass has the two most common species, Smooth Crabgrass (Digitaria ischaemum) and large crabgrass (Digitaria sanguinalis).

Smooth crabgrass has few hairs at its collar region next to the membranous ligule. As its name suggests, large or hairy crabgrass has hairy leaves and stems. Both these types are water weeds that spread quickly.


You can get rid of this pesky water weed by proper chemical control methods using Drive (quinclorac), Tenacity (mesotrione), Acclaim Extra (fenoxaprop), etc.

Post-emergence control can also be very effective for this type of grass. Moreover, this grass can die on its own in cooler seasons as it is the warm type.

5. Nimblewill (Muhlenbergia schreberi)

The Nimblewill is a warm-season perennial grass that forms mat-like patches. Therefore, it looks like other mat-forming blue green-leafed plants such as bermudagrass or creeping bentgrass.

You can distinguish this grass from its characteristic gray-green color, short, jagged, membranous ligule and coarse leaves.


Lawn care practices like increasing the mowing height, fertilizing in the fall and overseeding can help your lawn beat Nimblewill infestations. Applying nonselective systemic herbicides such as glyphosate on the young plant is also helpful.

4 Tips on How To Get Rid Of Water Grass

There are many different types of water weeds, and you’ll need to know which one is in your yard so that you can easily get rid of it.

The details mentioned above will help you in doing that. Let’s look at the most effective ways (a combination of cultural practices, chemical and biological control) to get rid of water weeds.

1. Increase Mowing Height

Lawns are often a hot spot for weeds, especially when it’s mowed too short. Yes, mowing very low to the ground allow water weeds to make their way in.

It may be difficult to mow frequently, but you have to do it to avoid water weeds establishing themselves as predators in your yard.

2. Water Deeply And Infrequently

The watering routine of water grass is the opposite of mowing. You have to water it infrequently to ensure that it saturates deep into the ground. It will prevent root rot and soil compaction, preventing weeds from spreading.

3. Use Herbicides

If you want to eliminate pesky weeds infesting your lawn, consider using herbicides. Know the grass type and apply herbicide accordingly. A rule of thumb is not to mow two days before or after applying a herbicide to let it penetrate properly.

4. Dig Up The Roots

If you want to get rid of that pesky weed in your lawn, then try digging them up. It’s not easy and takes some time, but it can be the most effective than other tips to get rid of water grass if done right.

If there is a small patch, you can easily pull it with your hands (taking out the underground rhizome) for prolonged eradication.

Make sure you don’t spread the seeds to other yard parts. Last but not the least, refill those bare patches with new sod for improved fertilization.


Hope this article resolves how to get rid of water grass. Now, you will have no difficulty in clearing up your lawn from these weedy turf patches. Reach up in the comment section below to know if the tips were useful. We also welcome any suggestions from your side!