Weed identification: what is this weed?
Weed identification comes down to four clues you can check in your own yard: is it a grass, a broadleaf or a sedge; what do the leaves look like; what color are the flowers; and how does it grow? Answer them in the identifier below to get the likely matches, then open each one for the fix that works on it.
Contents
- How do you identify a weed, step by step?
- Is it a grass, a broadleaf or a sedge?
- What do the leaves tell you?
- What color are the weed flowers?
- How does it grow?
- Annual or perennial: why does it matter?
- Common types of weeds at a glance
- Which lawn weed guide do you need?
- Tough, invasive and special-case weeds
- Other common weeds you can identify here
- What does your weed say about your yard?
- Can you identify weeds by photo?
- Common identification mistakes
- FAQ
Naming the weed is not a formality. A broadleaf lawn killer does nothing to crabgrass, a crabgrass product does nothing to nutsedge, and pulling the top off a perennial only wakes up the root. Once you know what you are dealing with, the right method, product and timing usually become obvious.
How do you identify a weed, step by step?
- Sort it into a groupGrass, broadleaf or sedge. This one check decides which products can work.
- Look at one leaf closelyShape (toothed, round, heart-shaped, arrow-shaped, three leaflets, spiny, fleshy), edges, hairs, and the pattern of veins.
- Check how the leaves attachIn pairs facing each other (opposite), staggered up the stem (alternate), in a ring (whorled) or in a flat circle at ground level (rosette). Roll the stem: square stems point to the mint family, such as creeping Charlie and henbit.
- Note the flowers or seed headsColor, shape and season. Many weeds are hard to tell apart until they bloom.
- Watch how it growsFlat rosette, low creeping mat, upright clump, tall stalks or a vine that climbs and twines.
- Dig one upA single taproot, a fibrous root ball, runners above ground, rhizomes below ground or small tubers each tell you how the weed comes back.
- Write down the seasonA weed that appears in fall and dies in early summer is a winter annual; one that shows up in late spring and dies at frost is a summer annual. Perennials return from the same roots every year.
Is it a grass, a broadleaf or a sedge?
All lawn and garden weeds fall into one of three groups. Getting this right saves you from buying the wrong product.
| Group | How to recognize it | Common examples | What controls it |
|---|---|---|---|
| Grassy weeds | Long, narrow blades with parallel veins; round or flattened hollow stems with joints (nodes) | Crabgrass, foxtail, torpedo grass | Pre-emergents for annual grasses; grass-specific post-emergents labeled for your lawn type |
| Broadleaf weeds | Wide leaves with a branching net of veins; often showy flowers | Dandelion, clover, creeping Charlie, plantain | Selective broadleaf herbicides (2,4-D, dicamba, MCPP, triclopyr, fluroxypyr) that spare most lawn grasses |
| Sedges | Grass-like but with a solid, triangular stem; blades often shiny and in sets of three | Yellow nutsedge, purple nutsedge, kyllinga | Sedge-specific products such as halosulfuron or sulfentrazone |
Quick test: “sedges have edges.” Roll the stem between your thumb and finger. If it feels triangular, it is a sedge, and neither grass nor broadleaf products will control it.
Weeds that look like grass
If a patch of “grass” is a different color, grows faster or has a different texture than the rest of the lawn, it is probably a weed. Nutsedge is lighter green and shinier, and shoots up a few days after mowing. Crabgrass has wider, lighter-green blades that splay out flat from a center and dies with the first hard frost. Foxtail forms clumps topped with bristly, bottlebrush seed heads. In Florida and along the Gulf Coast, stiff, upright blades that spread from sharp-tipped underground stems are often torpedo grass. Wild garlic and wild onion stand taller than the lawn in early spring and smell of onion when crushed; wild garlic leaves are round and hollow, wild onion leaves are flat and solid.
What do the leaves tell you?
Leaf shape is the clue the identifier asks about first, because it narrows the list fastest.
- Deeply toothed leaves in a rosette: dandelion. The leaf edges point back toward the center, and broken leaves ooze a milky sap.
- Three leaflets: white clover (rounded leaflets, often with a pale chevron), yellow woodsorrel (heart-shaped leaflets that look like a clover), and, on fences and tree trunks, poison ivy (pointed leaflets, the middle one on a longer stalk).
- Round, scalloped or heart-shaped leaves: creeping Charlie (square stems, minty smell, creeps and roots along the ground), wild violet (heart-shaped leaves in clumps), henbit and purple deadnettle (square stems, upright in spring).
- Wide, ribbed oval leaves flat on the ground: broadleaf plantain.
- Small leaves in pairs: chickweed (soft, pointed leaves, tiny white flowers), spotted spurge (tiny leaves, often with a red blotch, milky sap) and purslane (thick, fleshy leaves).
- Arrow-shaped leaves on a vine: field bindweed.
- Spiny leaves: thistle.
- No real leaves, just a soft green carpet: moss, which is a sign of shade, compaction or poor drainage rather than a weed you can spray away.
What color are the weed flowers?
Flowering weeds are easiest to name when they bloom, so a quick look at the flower color narrows the search.
| Flower color | Likely weeds | Season |
|---|---|---|
| White | White clover, chickweed, field bindweed (white to pink), Japanese knotweed (sprays of small flowers) | Spring to late summer; knotweed in late summer |
| Yellow | Dandelion, yellow woodsorrel, purslane (small, on fleshy stems), yellow nutsedge (yellowish-brown seed heads) | Spring through summer |
| Purple or blue | Creeping Charlie, henbit, purple deadnettle, wild violet, thistle | Spring for most; thistle in summer |
| None you can see | Crabgrass, foxtail, spurge (flowers are tiny), plantain (pencil-like seed spikes), moss | Summer for most |
White weeds in a lawn are most often clover or chickweed. A carpet of small purple flowers in early spring is usually henbit, purple deadnettle or creeping Charlie: check the stems and the leaf stalks to tell them apart (details below).
How does it grow?
The growth habit tells you how the weed spreads, which tells you how to remove it.
- Flat rosette: leaves radiate from one point at ground level, as in dandelion, plantain and wild violet. Mowing misses the leaves, so these survive in short lawns. Dig out the crown and root.
- Creeping mat: stems run along the ground and often root where they touch soil, as in creeping Charlie, clover, chickweed, spurge and purslane. Pull from the center and lift the whole mat.
- Upright clump: grassy weeds and sedges, henbit in spring. Clumps are easy to spot-treat.
- Tall, over 3 feet: thistle, Japanese knotweed, and young trees from blown-in seeds (see weed trees).
- Vine: bindweed twines around stems; poison ivy climbs with hairy aerial roots. Never pull a vine you have not identified with bare hands.
Annual or perennial: why does it matter?
The life cycle tells you whether to stop seeds or kill roots.
| Life cycle | How it lives | Examples | What to target |
|---|---|---|---|
| Summer annual | Sprouts in spring or summer, dies at frost, returns from seed | Crabgrass, foxtail, spurge, purslane | Seeds: pre-emergent in spring, pull before seeding |
| Winter annual | Sprouts in fall, overwinters small, flowers in spring, dies in early summer heat | Henbit, purple deadnettle, common chickweed | Seeds: pre-emergent in late summer or fall; treat small plants in fall |
| Biennial | Rosette the first year, flowers and dies the second | Bull thistle | Dig the rosette before it bolts |
| Perennial | Returns for years from roots, runners, rhizomes or tubers | Dandelion, clover, creeping Charlie, nutsedge, violets, bindweed, knotweed | Roots: remove them or use a systemic product, often in fall |
Timing follows from this table. The weed control calendar lays out the month-by-month tasks for northern, transition-zone and southern lawns.
Common types of weeds at a glance
| Weed | Type | Key feature | Usually found |
|---|---|---|---|
| Crabgrass | Grassy, summer annual | Light-green blades splaying flat from a center | Thin, sunny lawns; cracks |
| Foxtail | Grassy, summer annual | Bristly, bushy seed heads | Lawns, edges |
| Nutsedge | Sedge, perennial | Triangular stems, shiny blades, tubers | Wet spots in lawns |
| Dandelion | Broadleaf, perennial | Toothed rosette, taproot, puffball seeds | Lawns, beds |
| White clover | Broadleaf, perennial | Three round leaflets, white flower heads | Low-nitrogen lawns |
| Creeping Charlie | Broadleaf, perennial | Scalloped round leaves, square stems, minty smell | Shady lawns and beds |
| Wild violet | Broadleaf, perennial | Heart-shaped leaves, purple or white spring flowers | Shady lawns |
| Chickweed | Broadleaf, winter annual | Small paired leaves, tiny white star flowers | Lawns and beds in cool weather |
| Plantain | Broadleaf, perennial | Wide ribbed leaves, pencil-like seed spikes | Compacted lawns, paths |
| Henbit | Broadleaf, winter annual | Scalloped leaves hugging square stems | Thin lawns, beds in spring |
| Purslane | Broadleaf, summer annual | Thick, fleshy leaves on reddish stems | Beds, cracks, new lawns |
| Spotted spurge | Broadleaf, summer annual | Tiny paired leaves, red blotch, milky sap | Cracks, thin lawns, beds |
| Yellow woodsorrel | Broadleaf, perennial | Heart-shaped leaflets, yellow flowers | Lawns, beds, containers |
| Moss | Non-vascular plant | Soft green carpet, no true roots | Shady, compacted, wet spots |
Which lawn weed guide do you need?
Each lawn weed has its own guide with identification, look-alikes, removal by hand, natural and chemical options and prevention. For the overall approach, start with the lawn weeds guide.
Tough, invasive and special-case weeds
Some weeds need more than a lawn product, and a few are worth identifying for safety. Japanese knotweed spreads from deep rhizomes and regrows from small fragments. Poison ivy causes an itchy rash on contact, even from dead vines. Bindweed and Canada thistle have creeping roots that resprout from pieces left in the soil. Torpedo grass has no easy selective fix in some Southern lawns, and weed trees such as tree of heaven come back stronger when you simply cut them down. And some weeds are food: our edible weeds guide covers the common ones and their dangerous look-alikes.
Other common weeds you can identify here
These five weeds come up in the identifier and are common in lawns, beds and pavement cracks across the country.
Broadleaf plantain (and buckhorn plantain)
How to identify it: broadleaf plantain is a perennial that forms a flat rosette of smooth, oval leaves about 2 to 7 inches long. The leaves have several prominent veins running parallel to the edges and meeting at a broad leaf stalk. From summer on, it sends up slender, pencil-like spikes packed with tiny flowers and then seeds. Buckhorn plantain, its relative, has narrow, lance-shaped leaves and a short, cone-shaped flower head on a tall stalk.
Look-alikes: a young dandelion also grows as a rosette, but its leaves are deeply toothed. Plantain leaves are smooth-edged or slightly wavy and heavily ribbed.
What it tells you: plantain thrives in compacted soil with heavy foot traffic, so it shows up along paths, play areas and driveway edges.
How to control it: dig out the crown and roots when the soil is moist. In lawns, a selective broadleaf herbicide containing 2,4-D or triclopyr controls it; perennial broadleaf weeds are easiest to kill in fall. Core aeration and a denser lawn reduce the conditions it likes. Read and follow the label of any product you use.
Henbit and purple deadnettle
How to identify them: both are winter annuals in the mint family, with square stems. They sprout in fall, stay small over winter, then flower and set seed in spring before dying as temperatures rise in late spring and early summer. Henbit has rounded, scalloped leaves; the upper ones wrap directly around the stem with no leaf stalk. Its small, tubular, pinkish-purple flowers grow in whorls. Purple deadnettle has more triangular leaves on short stalks, and the leaves near the top are crowded and tinged red to purple.
Look-alikes: creeping Charlie also has square stems and purple flowers, but it is a perennial that creeps along the ground, roots at the leaf joints, has rounder leaves on stalks and smells minty when crushed. It is still there in midsummer; henbit is not.
How to control them: pull or hoe them before they flower; they have shallow roots. Herbicides work best on small plants in fall: products containing 2,4-D, dicamba, fluroxypyr or triclopyr are labeled for them in many lawns. By late spring the plants die on their own, so spraying flowering henbit is usually wasted effort. To prevent the next crop, a pre-emergent applied in late summer or early fall stops winter annual seeds, but skip it on areas you plan to overseed. A thick lawn, mowed at the right height, is the best long-term defense.
Common purslane
How to identify it: a summer annual that forms a low mat of reddish, fleshy stems radiating from a central root. The leaves are thick, smooth, succulent and paddle-shaped, and the small yellow flowers sit at the stem tips. It loves heat and shows up in vegetable beds, new lawns and pavement cracks from late spring on.
Look-alikes: spotted and prostrate spurge grow in the same places but have thin, wiry stems, tiny flat leaves and a milky sap when the stem is broken. Purslane sap is clear and watery. This matters if you plan to eat it: purslane is a well-known edible weed, spurge is not (see edible weeds).
How to control it: pull or hoe it while it is young, before it flowers and drops seed. Do not leave pulled plants on moist soil: the fleshy stems stay alive for days and broken pieces can reroot. Bag them or put them in a hot compost pile. Mulch bare soil in beds; a dense lawn keeps it out of turf. A pre-emergent applied before it sprouts can help in ornamental beds where the label allows.
Spotted and prostrate spurge
How to identify it: a summer annual that grows as a flat mat from a single taproot. The stems are thin, often reddish and hairy, and the leaves are tiny (about 1/8 to 1/2 inch), in pairs, frequently marked with a reddish-purple blotch in the middle. Break a stem and a white, milky sap appears. It thrives in hot weather, in thin or drought-stressed lawns, in sidewalk cracks and in mulched beds, and can set seed within a few weeks of sprouting.
Look-alikes: purslane (fleshy leaves, clear sap) and prostrate knotweed (bluish-green leaves, papery sheaths at the leaf joints, no milky sap).
How to control it: wear gloves, because the sap can irritate skin. Grip the plant at the center and pull slowly in moist soil; plants often snap at the crown and regrow if the root stays behind. Mulch at least 2 inches deep in beds. In lawns, a pre-emergent labeled for spurge, such as dithiopyr or pendimethalin, prevents seedlings if it is down before they sprout; spurge germinates later than crabgrass, in warmer soil, so check that an early-spring application is still active (the label gives how long it lasts and when to repeat). Young plants respond to broadleaf herbicides; large, mature mats are much harder to kill, so act early. A thick, well-watered lawn leaves it little room.
Yellow woodsorrel (oxalis)
How to identify it: leaves divided into three heart-shaped leaflets, like a clover, on thin stems; small yellow flowers with five petals; and narrow seed pods shaped like tiny okra that burst open when ripe and fling the seeds well away from the plant. Yellow woodsorrel is mostly upright and green; its relative creeping woodsorrel spreads along the ground, roots at the joints and often has purplish leaves. Both taste sour, from oxalic acid.
Look-alikes: white clover has rounded leaflets, often with a pale chevron, and white ball-shaped flower heads. Black medic has yellow flowers too, but in small round clusters, and its leaflets are oval rather than heart-shaped.
How to control it: pull scattered plants before they flower, taking the roots and runners. In lawns, products containing triclopyr or fluroxypyr are effective on woodsorrel; combination broadleaf products with 2,4-D and dicamba are also labeled for it. Most seeds sprout from late winter to early spring, so a pre-emergent containing prodiamine, pendimethalin or benefin, applied before then, cuts down new plants. Mulch beds and keep the lawn dense. Always check that a product is labeled for your grass type.
What does your weed say about your yard?
Many weeds point to a problem the lawn or bed has. Fixing the cause keeps the weed from coming back after you remove it.
| If you see | It often means | Fix |
|---|---|---|
| Clover | Low nitrogen | Fertilize at the rate your grass needs |
| Plantain | Compacted soil, foot traffic | Core aerate, redirect traffic |
| Nutsedge | Wet, poorly drained soil | Water less often, fix drainage |
| Moss, creeping Charlie, violets | Shade, damp soil, thin grass | Thin tree canopies, shade-tolerant grass or ground cover |
| Crabgrass, spurge | Thin turf, mowing too short, light frequent watering | Mow higher, water deeply and less often, overseed |
Can you identify weeds by photo?
Photo weed identification works well when the pictures show what a botanist would check. Plant ID apps give a quick first guess, but they confuse look-alikes such as purslane and spurge or henbit and creeping Charlie, so compare the suggestion with the features above before you act on it. Take these shots:
- One leaf, top and underside, in sharp focus.
- The stem where the leaves attach, to show their arrangement and any hairs.
- The flower or seed head, if there is one.
- The whole plant, and the roots once you dig it up.
For a definite answer, contact your county extension office. Extension services run by land-grant universities identify weeds for home gardeners, often from an emailed photo or a fresh sample. Bag the whole plant, roots included, between dry paper towels, keep it in the refrigerator and drop it off or mail it early in the week so it does not sit in a mailbox over a weekend. Extension staff can also tell you whether a plant is a regulated invasive in your state.
Common identification mistakes
- Calling every grassy weed crabgrass: nutsedge and torpedo grass need entirely different products.
- Spraying before you know the group: broadleaf products do nothing to grasses or sedges, and many grass products damage lawn turf.
- Treating a dying weed: henbit, deadnettle and chickweed die in early summer anyway; their fix is fall prevention.
- Pulling an unknown vine barehanded: a three-leaflet vine on a fence may be poison ivy. Check first.
- Eating a weed identified from one photo: several edible weeds have toxic look-alikes.
Once you have a name, the next step is choosing the method: the weed killers guide compares homemade, natural and store-bought options, and the garden weeds guide covers beds, mulch, driveways and gravel.
FAQ
How do I identify a weed in my lawn?
Start with the group: pinch the stem and roll it between your fingers. A triangular stem means a sedge, a round or flat stem with long narrow blades means a grassy weed, and wide leaves with a net of veins mean a broadleaf weed. Then check the leaf shape, the flower color and how the plant grows (flat rosette, creeping mat, upright clump or vine). The weed identifier at the top of this page combines those clues for you.
Can I identify a weed from a photo?
Often, yes, if the photo is good. Take a close-up of a single leaf (top and underside), one of the stem where the leaves attach, one of the flower or seed head, and one of the whole plant. Plant ID apps give a useful first guess, but always compare the result with the look-alikes before you spray. If you are still unsure, your county extension office can identify a sample.
What are the main types of weeds?
Weeds are sorted two ways. By form: grassy weeds (crabgrass, foxtail), broadleaf weeds (dandelion, clover, plantain) and sedges (nutsedge). By life cycle: summer annuals, winter annuals, biennials and perennials. Each combination calls for a different control method, which is why identification comes first.
What weeds look like grass?
Crabgrass, foxtail, nutsedge, torpedo grass and wild garlic or wild onion are the usual suspects. Nutsedge has a triangular stem and shiny blades that grow faster than the lawn; wild garlic has hollow, round leaves and smells of garlic when crushed. Grassy weeds need grass-specific products, and sedges need sedge products: a broadleaf killer will not touch any of them.
What are the small white flower weeds in my lawn?
Where can I get a weed identified for free?
Your county extension office, part of your state’s land-grant university, can identify weeds for home gardeners. Many offices accept a photo by email; others prefer a fresh sample. Bag the whole plant, roots included, between dry paper towels, keep it in the refrigerator and bring or mail it early in the week.
Related
- Lawn weedsCommon lawn weeds by type (grassy, broadleaf, sedge), what each one says about your lawn, and the right control and timing to get rid of weeds in grass.
- Weed killersWhich weed killer do you need? Selective or non-selective, systemic or contact, pre- or post-emergent, organic or homemade, matched to lawn, beds and driveway.
- Garden beds, driveways & gravelGarden weeds in beds, vegetable plots, driveways and gravel: identify the common ones, pick the right method and tools for each place, and stop reseeding.
- Weed control calendarThe best time to spray weed killer by weed, season and region, plus the weather rules on the label. Pick your region for this month's lawn to-do list.
Updated October 3, 2026