16 Weeds That Look Like Grass

Last Updated on December 24, 2023 by Kimberly Crawford

The striking thing about weeds would be that they easily blend with turf grasses. As a matter of fact, they can even establish their roots way earlier than weeds (which make them identifiable for the trained eye).

When they establish their roots in the lawn earlier, chances are, they have sucked out most of the nutrients that are for the grass supposedly.

Because of these, you should be knowledgeable about what common weeds look like grass. In this post, we rundown these weeds for you to easily identify which ones to uproot or control immediately.

In this article

What are weeds?

In agriculture, any unwanted plant is called a weed. They are unwanted precisely because they are perceived to suck the nutrients that are supposed to be enjoyed by the prized crops. Like plants, weeds can be categorized into annuals, biennials, and perennials.

Some classifications are also based on where they naturally grow. For instance, there are so called facultative weeds which grow in wild environments but can find their way in cultivated lands through wild critters. There are also obligate weeds which can only thrive in cultivated lands and other disturbed lands.

Weeds that look like grass

Going straight to the focus of this post, here are some of the weeds that look like grass. This covers some major differentiating characteristics, growth habit, and the months they establish their roots.

1. Annual Bluegrass (Poa annua)

This one is usually mistaken for the Kentucky bluegrass, but you could identify it with its brighter green color and lighter texture. It also sports a longer ligule which holds the base of the grass clump.

Its leaves are also curvier compared to Kentucky bluegrass and thrives in damp and cool climates. In the summer, they turn into papery, brown grass. Spray foramsulfuron before spring to inhibit their growth.

2. Blue Fescue (Festuca glauca)

This one is used for some lawns because of its striking blue green leaves. It is used in landscapes as accent grass or as ground cover. It grows to up to 12-inches in a mounding habit and thrives in cool seasons. The leaves are spiky and produce bright green blooms in the spring.

This should not be mistaken for other fescue grasses like the tall fescue. If you do not want them to pester your landscape, you can manually pull them by the root or spray herbicides which contain glyphosate.

3. Broom sedge (Andropogon virginicus)

This one is an interesting warm season perennial weed grass. It thrives in soils with low acidity, low soil fertility, lots of sun, and found in masses in railroad tracks and abandoned lots. It grows in bunches, basically, and its color transforms from dull green to coppery orange at fall.

You must note that this one is not a true sedge so you cannot use the vinegar solution to control it. Most pre-emergent herbicides are also not effective for this. The best control mechanism for this would be liming and proper turf fertilization.

4. Carpetgrass (Axonopus sp.)

This one is also called the blanket grass, and it thrives in wet, shady, and boggy areas with high acid content. It grows tall at 12-inches and forms mats of dense, dull green and coarse textured leaves. It is a warm climate perennial and forms seed heads that look like crabgrass during the summer.

The interesting thing about this is that it turns brown as soon as its range of high temperature slightly goes down. Spraying oryzalin before spring is a good pre-emergent herbicide to use. Natural control solutions include salt and water.

5. Crabgrass (Digitaria sanguinalis)

This is considered as the most common lawn weed and it is most identifiable for its horizontal and fast growth habit. It gets its name for its crab-shaped growth. They sport a bright green color and a wide central fold for the leaves. The central fold is larger than most lawn weed grasses.

This one becomes invasive in hot and humid climates. Unlike other weeds, this one can be controlled using vinegar at 5% acidity. Just spray a vinegar solution thrice a week before spring to control its growth. Herbicides with quinclorac are also effective in deterring crabgrass.

6. Creeping bentgrass (Agrostis palustris)

This is another cool weed grass which is identifiable for fine textured and dense mats of gray green patches of grass growing aggressively through its stolon. As such, you would easily spot it for being that bright green patch in the turf.

Unlike other weed grasses, its growth is quite tolerated in golf courses because of its puffy growth. During hot seasons or when the temperature gets up erratically, the leaves turn brown. To control this weed grass, the best herbicide to use would be mesotrione.

7. Dandelion (Taraxacum)

This one is considered as a broadleaf perennial which stands at 12-inches in height. It is a common lawn weed with very long taproots. The leaves look like crabgrass and as it matures, it sports yellow puffballs which easily flies with the wind. Being flown everywhere makes it an invasive lawn weed.

To prevent dandelions from encroaching your garden or lawn, mulch regularly. You can also pull them by the roots or use herbicides that do not have an effect on turf grass.

8. Foxtail (Setaria sp.)

This one is another common weed grass which grows in any soil condition, producing spikey bottle brush flowers in the summer and grows at large clumps of grass measuring to at least 40-inches across. The three main species of foxtail weed grass would be yellow, green, and giant foxtail.

For treatment, vinegar dowsing is effective for small patches but for larger ones, the use of non-selective herbicide or herbicides containing acetochlor. They have to be sprayed repeatedly the entire summer.

9. Goosegrass (Eleusine indica)

This annual weed grass is identifiable for its silver green color. It gets its name from its flowerhead featuring clumps of finger-like leaf strands spreading like a goose’s foot. It follows the same spread as crabgrass and grows to up to 16-inches.

This one thrives in poor draining and compacted soils. As such, the best solution to discourage growth would be good soil aeration especially during spring. If you want an herbicide solution, choose ones with trifluralin and benefin content. Mesotrione and dithiopyr also work.

10. Johnsongrass (Sorghum halepense)

At first glance, you would mistaken Johnson grass for corn seedlings. It reaches a peak height of 7ft and its leaves are distinguishable for their bright green color with a prominent white vein running along the center. The leaves are 1-2-inches wide, sporting purple flowers from spring up to the first frost.

If you do not want to use herbicides to treat this, you can uproot them by the root and then douse the space up with vinegar to control future growth. You can also re-sod or till the soil by fall to expose the rhizomes to cooler temperature and eventually kill them. But if large patches are the ones in question, you can use herbicides with sulfosulfuron.

11. Nutsedge (Cyperus sp.)

This perennial weed comes in two species: the purple and yellow nutsedge. They thrive in cool and wet locations sporting long and narrow leaves. During the summer, it produces brush-like flowers that are yellow in mid-summer and then turn into purplish red in late summer.

It gets its name from the nutlets found in its root clumps. Overwatering the lawn makes it grow aggressively and the best solution to control it would be using post-emergent herbicides which specifically contain sulfosulfuron.

12. Path Rush/Slender rush (Juncus Tenuis)

This one is very familiar in abandoned lots as well fields. It can grow to up to 2ft and is identifiable for its slender stems, narrow and long, and upright leaves. It aggressively grows from rhizomes, so it is quite challenging to control them and permanently get rid of them.

Aside from these, path rush is also resistant to herbicides, so you must manually dig the root up if you want to control them. Another control mechanism is to keep them short through mowing. This way, the seed heads are cut to control them from being distributed.

13. Quackgrass (Elymus repens)

This is a cool climate weed grass which also goes by the name common crouch. It is mostly identified for its finger-like leaves, clumped on multiple stems, and leaves that super extend out. It forms ash blue-green patches and follows a rhizomatic growth.

When it comes to treatment, non-selective herbicides can be considered but must be used sparingly because it could kill turf grasses. As such, the best treatment would be digging it up by the roots and then covering it with black plastic at summer’s peak.

14. Smooth Bromegrass (Bromus Ramosus Ramosus)

This one is a fast grower and is very invasive. It has a rhizomatic growth and spread and once the roots are established, it is said that it would be near impossible to get rid of it. The good news is that, with regular mowing, you are limiting their annual growth which also leads them to naturally die off.

Also, it is very important to keep the lawn healthy to control the bromegrass from thriving. But if you suspect uncontrolled, aggressive growth, consider pre-emergent herbicides that are not harmful for turf grass.

15. Yellow Salsify (Tragopogon Dubius)

In its native locations of Asia and Europe, this one is a usual sight but in North America, it is considered as invasive. They thrive in sunny locations, blooming yellow flowers during the summer and then followed by large puffballs at the dawn of fall.

The interesting thing about this is that the roots are dug out and cooked as a traditional delicacy in some parts of southern and central Europe as well as north and central Asia. Archives establish that they taste like oysters. The best control for this one is digging them up by the root or mulching regularly to keep the lawn healthy.

16. Wild garlic (Allium ursinum)

This one is a fast-growing weed, growing tall and well, smelling like garlic throughout spring so it is easy to spot. They usually grow in clumps, and they stand higher than your turf grass. Interestingly, since they also grow from bulbs, they can be dug out and then be cooked.

Their growing season would be spring and fall and then grow dormant the entire summer. For wild garlic control, you must dig them up by the bulb. You can also find an appropriate herbicide to permanently kill off wild garlic. They are not to be mistaken with wild onions.

Related: How to Plant Garlic At Home

FAQs

What weeds do not look like grass?

There are also a lot of weeds that you can mistake for ground cover plants and if you are wondering what they are, you can refer to this list here.

Oxalis
Bindweed
White clover
Creeping Charlie
Lamb’s Quarter
Dayflower
Purslane
Wild violet
Smartweed
Quickweed
Pig weed
Canada thistle
Knot weed
Pokeweed
Black nightshade
Henbit
Nettle
Prostrate spurge
Chickweed
Ragweed

What weeds are the hardest to kill?

Just so you could prepare yourself for what unexpectedly could grow in the lawn or garden, you must know the weeds that are hardest to kill. Here is a list of these weeds.

Banish weeds
Bittercress
Burdock
Chickweed
Crabgrass
Creeping Charlie
Clover
Cudweed
Dandelion
Field Bindweed
Ground Ivy
Kudzu
Johnson grass
Lamb’s Quarter
Nutsedge
Purslane
Quack grass
Water hyacinth

What are the worst weeds?

You must consider the fact that not all weeds are invasive universally across all regions and even US states for that matter. But if there is one thing that we could all agree on, it is that these are the worst weeds that could grace your garden or lawn.

Wild violet
Virginia buttonweed
Ground ivy
Canada thistle
Dandelion
Crabgrass
Clover
Mile-a-minute weed
Spotted spurge
Wood sorrel
Mugwort

Are there advantages of weeds?

Interestingly, there are. If you are curious as to what these could be, here are some of the listed, most common advantages of weeds in the garden or lawn.

It is said that some weeds bring up water, organic matter and nutrients that are deeply in the ground. With these, they make the soil more fertile as they feed microbes and plants.
Some weeds are helpful in making the soil less compact and in controlling soil erosion.
Weeds are good garden health indicators. Their presence means that some soil components need to be amended.
Interestingly, some weeds are said to balance the nutritional components of the soil. However, this function can last for a couple of years or up to decades even.
Weeds encourage biodiversity around the vicinity. They provide food to microbes as well as animals and insects.

When is the best time to pull off weeds?

The best time to control the weeds through pulling them off by the root would be during seasons or climates when the soil is damp and moist. However, if the patches have become larger and there is need for drastic weed control, you might have to use herbicides. Just choose the ones that are considered as not harmful to turf grass.

Related: How to Get a Perfect Lawn

How do you kill weeds naturally?

If you are not into herbicides, here are some of the DIY steps that you can employ to naturally kill weeds in your garden or lawn.

Pulling them off by hand
Sprinkling cornmeal
Regular mulching
Dousing vinegar
Covering them with newspaper
Scalding the ground with boiling water
Applying table salt on the plant’s base
Apply herbicidal soap (with vinegar)
Use weed torch (but research on how to do it first)

What are the best herbicides to use for hard to kill weeds?

Note that there are specific chemical substances that are appropriate to specific weeds. And since there are just weeds that are harder to kill, these are the best herbicides that are all-around when it comes to weed killing.

What chemical do professionals use in killing weeds?

There are two types of herbicides for weed killing: pre-emergent and post-emergent herbicides. For this reason, you must know which weeds can be killed by each. With respect to what chemicals used by professionals in weed killing, it would herbicides that contain the following:

Trifluralin
Oryzalin
Glyphosate
Sethoxydim
Fluazifop Butyl

Conclusion

As have been mentioned, it is imperative to know which grass is which because some might be low-key harassing your turf grasses’ growth. But more than this, you must understand that the presence of weed grass is an indication of poor lawn health and regularly amending that can help in permanently getting rid of unwanted weed grass.

There are a lot of weed control mechanisms that you can explore. The good news is that you can use non-herbicide and herbicide choices to help you in weed control. With all things considered, knowing the weed grasses that often grace your turf, how they look like and what you can do to control their growth should hold things under control.

16 Weeds That Look Like Grass

What are weeds?