15 Weeds That Look Like Grass: How to Identify and Deal With Each One

There is a particular kind of frustration that comes from staring at your lawn, knowing something is off, but not being able to put your finger on it. The grass looks slightly uneven in places. Some patches grow faster than others. A few sections have a different texture or color — but it all still looks like grass.

What you are likely dealing with are grass-like weeds. These are plants that have evolved to mimic the appearance of turf grass closely enough to go unnoticed for weeks or even entire growing seasons. By the time most homeowners realize something is wrong, these weeds have already spread, rooted deeply, and made themselves very comfortable.

This guide introduces the 15 most common weeds that look like grass, how to tell them apart from your lawn, and what you can do about each one.

Why Grass-Like Weeds Are So Difficult to Manage

Most people can spot a dandelion. Its broad, jagged leaves and bright yellow flower make it an obvious outsider in a sea of grass. But grass-like weeds do not give you that kind of visual advantage. They blend in. They grow at similar heights. Some even thrive in the same conditions your lawn grass prefers.

This visual similarity is not accidental. Many of these weeds belong to the same plant families as turfgrass — the grass family (Poaceae) and the sedge family (Cyperaceae). Others are from different families entirely but have developed narrow, elongated leaves that convincingly imitate the look of grass.

The result is that homeowners often mow over them repeatedly, unknowingly spreading seeds or encouraging vegetative spread, while thinking they are just dealing with an unruly patch of lawn.

Early identification is everything. The sooner you recognize a grass-like weed, the easier it is to remove or treat.

1. Crabgrass (Digitaria spp.)

Crabgrass is arguably the most infamous grass impersonator on this list. It is an annual grassy weed that germinates in late spring when soil temperatures warm up, then spreads aggressively throughout summer.

Young crabgrass looks almost identical to regular lawn grass. As it matures, though, the differences become clearer. The leaves are wider and coarser than most turfgrasses. The plant grows in a low, spreading, crab-like pattern — which is exactly where its name comes from. Stems radiate outward from a central point, lying almost flat against the soil.

Crabgrass thrives in thin, stressed, or compacted lawns. It loves heat and drought conditions that weaken turf grass. Each plant can produce up to 150,000 seeds in a single season, which is what makes it so persistent year after year.

How to control it: Pre-emergent herbicides applied in early spring are the most effective strategy. Post-emergent products containing quinclorac or fenoxaprop work on established plants. Maintaining a thick, healthy lawn is the best long-term prevention.

2. Annual Bluegrass (Poa annua)

Annual bluegrass, or Poa annua, is one of the most widespread grass weeds in the world. It is a cool-season annual that germinates in fall and early spring, producing dense, low-growing clumps that can infiltrate even well-maintained lawns.

It closely resembles Kentucky bluegrass and ryegrass, especially when young. The key distinction is the lighter, almost lime-green color of its leaves and the distinctive boat-shaped leaf tips. It also produces visible seed heads even when mowed very short, giving infested lawns a whitish or patchy appearance.

Annual bluegrass tends to die out in summer heat, leaving bare patches behind — which, ironically, create ideal conditions for the next generation of seeds to germinate in fall.

How to control it: Pre-emergent herbicides applied in late summer to early fall break the germination cycle. Mesotrione (found in Tenacity) can control established Poa annua in certain turf types. Good lawn density and proper mowing height help crowd it out.

3. Quackgrass (Elymus repens)

Quackgrass is a perennial grassy weed that is notoriously difficult to eliminate. Unlike annual weeds, it does not die with the season. It spreads both by seed and through underground rhizomes — horizontal root structures that extend through the soil and generate new shoots.

It looks very similar to common lawn grasses but has a few distinguishing features. The leaves are broader than most fine-bladed grasses and have a rough, sandpaper-like texture on the upper surface. The auricles — small claw-like projections at the base of the leaf blade — are a reliable identifying feature. The stems are also coarser than typical turf grass.

Quackgrass grows faster than surrounding grass, so patches tend to appear taller and greener after mowing.

How to control it: Because of its rhizome system, pulling it out by hand rarely works — pieces of root left behind regenerate. In lawns, selective herbicides with limited effectiveness exist, but complete eradication often requires non-selective treatment of the affected area followed by reseeding.

4. Nutsedge (Cyperus esculentus and Cyperus rotundus)

Yellow nutsedge and purple nutsedge are among the most commonly misidentified lawn weeds. They are not true grasses — they belong to the sedge family — but their narrow, upright leaves make them look enough like grass to fool most people at first glance.

The easiest way to identify nutsedge is the triangular stem. True grasses have round or flattened stems. If you roll the stem between your fingers and it feels like it has edges, you are likely holding a sedge. The leaves are also glossy and bright yellow-green, noticeably different from the matte surface of most lawn grasses. Nutsedge also grows significantly faster than surrounding turf, particularly in wet areas.

It spreads through underground tubers called nutlets, which can survive in the soil for years. This makes nutsedge one of the most persistent lawn weeds you can encounter.

How to control it: Standard herbicides do not work on sedges. Use sedge-specific products such as halosulfuron-methyl (Sedgehammer) or sulfentrazone (Dismiss). Improving drainage in waterlogged areas reduces future infestations.

5. Goosegrass (Eleusine indica)

Goosegrass is a warm-season annual grassy weed that bears a strong resemblance to crabgrass. It grows in a similar flat, rosette-like pattern, but there are differences. The leaves of goosegrass are darker green with a distinctive white or silvery midrib running down the center. The stems are also noticeably flattened and often have a pale, almost white base.

It is commonly found in areas with compacted soil — driveways, sidewalk edges, high-traffic lawn areas — because it tolerates compaction better than most plants. If your lawn suffers from heavy foot traffic, goosegrass is a likely visitor.

How to control it: Pre-emergent herbicides applied in spring prevent germination. Post-emergent control is more difficult; products containing fenoxaprop or fluazifop offer some effectiveness. Aerating compacted soil removes the conditions that favor goosegrass.

6. Tall Fescue (as a weed in fine-turf lawns)

This one requires a bit of context. Tall fescue is a legitimate, widely planted lawn grass — and a good one. However, when tall fescue volunteer plants grow in a lawn seeded with fine-bladed grasses like Kentucky bluegrass or creeping bentgrass, they become weeds.

Tall fescue has noticeably wider, coarser leaves than fine-textured grasses. It forms distinct clumps that stand out visually, with a darker green color and a rougher texture. In a fine-turf lawn, these clumps look unnatural and disruptive.

Because tall fescue is a desirable grass species in many situations, there is no selective herbicide that will kill it without damaging surrounding turf. This creates a frustrating control challenge.

How to control it: Small clumps can be dug out by hand with a weeding tool, removing as much of the root system as possible. Larger infestations may require spot-treating with a non-selective herbicide and reseeding those areas.

7. Creeping Bentgrass (Agrostis stolonifera)

Creeping bentgrass is another case of a legitimate turf grass becoming a weed in the wrong setting. It is widely used on golf courses and putting greens. But when it invades a home lawn of bluegrass or fescue, it creates patches that look pale, fine-textured, and matted — clearly different from the surrounding turf.

These patches tend to be grayish-green rather than bright green and lie lower to the ground because of how bentgrass grows on stolons (above-ground stems). The patches are most visible in summer, when heat stress causes bentgrass to thin out and look ragged while surrounding grass remains healthier.

How to control it: There are no selective herbicides that target bentgrass in mixed lawns without some damage to surrounding grass. Renovation of severely infested areas with glyphosate, followed by reseeding, is usually the most effective approach.

8. Nimblewill (Muhlenbergia schreberi)

Nimblewill is a native warm-season perennial grass that invades cool-season lawns. It goes dormant in winter, turning brown and straw-like, then greens up again in late spring. This dormancy cycle causes visible brown patches in otherwise green lawns during fall and early spring.

When actively growing, nimblewill has fine, short leaves and a blue-green color. It spreads by stolons, forming low, mat-like patches that feel spongy underfoot. The texture is distinctly different from most cool-season grasses, but the difference can be subtle enough to miss casually.

How to control it: Tenacity (mesotrione) is one of the few selective options that controls nimblewill in cool-season lawns. Multiple applications are typically required. Hand-removal works for small patches if done carefully.

9. Foxtail (Setaria spp.)

There are several species of foxtail — green foxtail, yellow foxtail, and giant foxtail being the most common. They are annual grassy weeds that germinate in spring and grow through summer, producing distinctive bristly, cylindrical seed heads that look like a fox’s tail. Before those seed heads appear, though, they look quite a lot like regular lawn grass.

Young foxtail plants have flat, wide leaf blades with a rough texture. Yellow foxtail has a distinctive spiral twist at the base of the leaf blade, which is useful for identification. The leaves are also wider and coarser than most lawn grasses.

Foxtail is most common in bare or thin lawn areas, along edges, and in recently disturbed soil. The seed heads are a clear identifier once they emerge, but by that point the plant is already mature and producing seeds.

How to control it: Pre-emergent herbicides applied in spring prevent germination. Post-emergent products containing fluazifop or sethoxydim can control established foxtail in broadleaf lawns or garden beds. In turfgrass, Tenacity provides some control.

10. Barnyard Grass (Echinochloa crus-galli)

Barnyard grass is a coarse annual grassy weed that can grow remarkably fast under warm, moist conditions. It is common in lawns, gardens, and along water edges. In its early stages, it closely resembles crabgrass or large crabgrass, with wide, flat leaf blades and a sprawling growth habit.

The distinguishing feature of barnyard grass is the absence of a ligule — the small membrane or fringe found at the junction between the leaf blade and the leaf sheath in most true grasses. This is a technical detail, but it is reliable. The stems are also thick and often reddish-purple near the base, and the plant can grow tall quickly if not mowed.

How to control it: Pre-emergent herbicides are effective. In turfgrass settings, products like quinclorac control barnyard grass post-emergence. Pulling young plants before they set seed prevents the problem from compounding.

11. Orchard Grass (Dactylis glomerata)

Orchard grass is a perennial cool-season grass that is legitimately used in pastures and hay fields. In a home lawn, however, it is a weed. It forms coarse, upright clumps with wide, flat leaf blades that are distinctly V-shaped in cross-section — a useful identification feature. The leaf surface is dull and rough.

The clumps are persistent and grow faster than surrounding turf grass, making them highly visible after mowing. They also tend to look lighter green or even slightly bluish compared to Kentucky bluegrass or fescue.

Like tall fescue, the challenge with orchard grass is that it is a grass species with no good selective herbicide option.

How to control it: Dig out individual clumps carefully, removing the entire root crown. Spot-treating with a non-selective herbicide is necessary for larger infestations, followed by reseeding.

12. Wild Garlic and Wild Onion (Allium vineale and Allium canadense)

Wild garlic and wild onion are not true grasses, but their long, narrow, tube-like leaves grow upright and blend remarkably well into a lawn. They are perennial plants that grow from underground bulbs, emerging in fall and growing through spring before dying back in summer.

The most reliable way to identify them is by smell. Crush a leaf between your fingers — if it smells like garlic or onion, you have found your weed. The hollow, tubular leaves of wild garlic are also distinct from the flat leaves of most grasses. Wild onion has flat leaves rather than hollow ones, but the smell test applies to both.

They are tough to eradicate because the bulbs persist in the soil even after the top growth is removed.

How to control it: Products containing metsulfuron-methyl or a combination of 2,4-D, MCPP, and Dicamba (such as Trimec) provide reasonable control. Multiple fall applications are usually needed. Digging out bulbs is effective for small patches but requires thoroughness — any bulb fragment left behind will regrow.

13. Smooth Brome (Bromus inermis)

Smooth brome is a perennial cool-season grass common in roadsides, pastures, and disturbed areas. It spreads by rhizomes and can invade home lawns from surrounding areas. The leaves are broad, flat, and smooth with an unusual “W”-shaped crease or wrinkle across the middle of the blade — a feature unique enough to be a reliable identifier.

It grows in loose clumps and tends to appear lighter green than most lawn grasses. The plant is tough and competitive, particularly in cooler climates.

How to control it: Like other clump-forming perennial grasses, removal usually requires a combination of hand-digging and spot-treatment with non-selective herbicides. Maintaining a dense lawn minimizes the chances of smooth brome gaining a foothold.

14. Kikuyu Grass (Pennisetum clandestinum)

Kikuyu grass is a warm-season perennial that is used as a turf grass in some warm climates — particularly in parts of Africa, Australia, and California. In lawns planted with cool-season grasses or other warm-season varieties, however, it becomes a highly invasive and very difficult-to-control weed.

It spreads aggressively through both above-ground stolons and underground rhizomes. The leaves are coarse and hairy, with a distinctive V-shape to the leaf blade when young. It forms dense, thick mats that crowd out other grass species. In cooler months, it turns brown and dormant, creating unsightly patches.

How to control it: Kikuyu grass is notoriously resistant to most selective herbicides. Fluazifop provides some suppression but rarely achieves full eradication. In severe infestations, killing the entire affected area with glyphosate and resodding or reseeding is the most reliable solution.

15. Velvetgrass (Holcus lanatus)

Velvetgrass is a perennial cool-season grass that invades lawns, particularly in moist climates. It gets its name from the soft, velvety texture of its leaves and stems, which are covered in fine, downy hairs. While this texture makes it easy to identify by touch, a casual glance at a lawn can easily overlook it.

The leaves are broad and grayish-green, and the plant forms loose, spreading clumps. It tends to stand out more clearly in summer when surrounding lawn grasses are stressed, because velvetgrass maintains a distinctly different color and texture.

It is common in the Pacific Northwest, coastal regions, and other areas with frequent rainfall. Like most clump-forming perennial grasses, it has no selective herbicide option.

How to control it: Hand removal of small clumps is practical when the infestation is caught early. For larger areas, a combination of non-selective herbicide treatment and lawn renovation is the most effective route.

A Quick Identification Summary

Identifying grass-like weeds correctly before choosing a control method saves both time and money. Here are some general clues to watch for.

Stem shape is one of the most reliable tools. Grasses have round or flattened stems. Sedges have triangular stems. Feeling the stem of a suspicious plant takes only a moment and immediately separates sedges from grasses.

Leaf texture and width can also narrow things down. Coarser, wider leaves often point to weedy species like crabgrass, barnyard grass, or orchard grass. Unusually fine or blue-green leaves might suggest creeping bentgrass or annual bluegrass.

Growth pattern is another clue. Spreading, low-growing rosette patterns indicate crabgrass or goosegrass. Upright, fast-growing clumps suggest quackgrass, tall fescue, or orchard grass. Mat-like patches that feel soft and spongy point toward nimblewill or creeping bentgrass.

Color differences are among the first things experienced lawn care professionals notice. Patches that are noticeably lighter, darker, yellower, or bluer than the surrounding turf deserve closer inspection.

Smell distinguishes wild garlic and wild onion immediately.

And if all else fails, pulling a small sample and comparing it to an identification guide — or sending a photo to your local cooperative extension office — is always a reasonable approach.

General Prevention Strategies

No weed can easily invade a thick, healthy, well-managed lawn. Most grass-like weeds exploit the same set of vulnerabilities: thin grass coverage, compacted soil, inconsistent moisture, poor nutrition, and improper mowing height.

Mowing at the recommended height for your grass species — generally 3 to 4 inches for most cool-season grasses — shades the soil surface and prevents many weed seeds from germinating. Overseeding thin areas in fall removes the bare soil patches that serve as entry points for annual weeds. Core aeration reduces compaction, which directly discourages goosegrass, crabgrass, and other stress-loving weeds.

Pre-emergent herbicides, applied at the right time each year, can interrupt the germination cycle of many annual grass weeds before they become visible problems. Timing these applications correctly — matched to your region’s soil temperature patterns — is the most critical factor in their success.

Final Thoughts

The 15 weeds on this list share one thing in common: they benefit from being overlooked. The longer they go unidentified, the more established they become, the more seeds they produce, and the harder they are to remove.

Taking a closer look at your lawn — not just an appreciative glance from the porch, but an actual walk-through with attention to texture, color, growth patterns, and stem shape — is the first and most important step in lawn weed management. You do not need to be a botanist. You just need to notice when something looks slightly wrong and take a moment to investigate.

Once you know what you are dealing with, the path forward is clearer. Whether that means a targeted herbicide application, a bit of hand-weeding, or a full renovation of a problem area, the right solution starts with the right identification.

A lawn worth growing is worth paying attention to. The weeds you see — and the ones hiding in plain sight — are worth knowing by name.

References

1. University of California Agriculture and Natural Resources — Grassy Weed Identification in Turfgrass. https://ipm.ucanr.edu/PMG/weeds/grass_weeds.html
2. Penn State Extension — Weed Identification and Management in Home Lawns. https://extension.psu.edu/weed-management-in-home-lawns
3. Purdue University Extension — Turfgrass Weed Control for Professionals. https://www.extension.purdue.edu/extmedia/BP/BP-68-W.pdf
4. University of Florida IFAS Extension — Identification and Biology of Weeds in Florida Turfgrass.https://edis.ifas.ufl.edu/publication/WG056
5. Michigan State University Extension — Common Grass and Sedge Weeds of the Great Lakes Region. https://www.canr.msu.edu/resources/common-weeds-of-michigan-lawns