Lawn Weed Identification Chart (2026)
Published: April 23, 2026
Correct identification is the first and most important step in weed control — the same herbicide that kills dandelions can damage St. Augustine, and broadleaf herbicides don't touch grassy weeds. American lawns host three weed categories: broadleaf weeds (dandelion, clover, plantain), grassy weeds (crabgrass, goosegrass, foxtail), and sedges (nutsedge, kyllinga). Each category has different control products and different treatment timing. This chart walks through the 20+ most common US lawn weeds with identification features and control recommendations.
Broadleaf Weeds Quick Reference
| Weed | Identification | Season | Control |
|---|---|---|---|
| Dandelion | Yellow flowers, rosette, deep taproot, milky sap | Spring, fall | 2,4-D + dicamba; fall treatment best |
| White Clover | 3 leaflets, white flower heads, stolons | Summer – fall | Triclopyr; correct nitrogen deficiency |
| Plantain (broadleaf) | Ribbed oval leaves in rosette, spiked flower | Spring – fall | 2,4-D + MCPP |
| Buckhorn Plantain | Narrow lance leaves, spiked flower | Spring – fall | Triclopyr + 2,4-D |
| Ground Ivy (Creeping Charlie) | Round scalloped leaves, purple flowers, vine-like | Spring, fall | Triclopyr (essential) |
| Wild Violet | Heart-shaped leaves, purple flowers, rhizomes | Spring | Triclopyr; multiple applications |
| Henbit | Square stems, whorled leaves, purple flowers | Fall – spring | Fall pre-emergent; 2,4-D post-emergent |
| Chickweed (Common) | Opposite oval leaves, white 5-petal flowers | Fall – spring | Fall pre-emergent; 2,4-D post-emergent |
| Spotted Spurge | Small leaves with purple spot, milky sap | Summer | Quinclorac, dicamba |
| Prostrate Knotweed | Thread-like stems, small leaves, flat mat | Summer | Pre-emergent; triclopyr post-emergent |
| Purslane | Succulent leaves, yellow flowers, mat-forming | Summer | 2,4-D + dicamba; pull by hand |
| Oxalis (Yellow Woodsorrel) | Clover-like leaves but sour taste, yellow flowers | Year-round | Triclopyr + 2,4-D |
| Creeping Speedwell | Small oval leaves, blue flowers, mat-forming | Spring | Triclopyr (tough to kill) |
| Black Medic | Yellow clover-like flowers, trifoliate leaves | Summer | Correct nitrogen; 2,4-D + dicamba |
| Thistle (Canada) | Spiny leaves, pink-purple flowers, rhizomes | Summer | Clopyralid, triclopyr |
Grassy Weeds Quick Reference
| Weed | Identification | Season | Control |
|---|---|---|---|
| Crabgrass | Wide flat blades, star pattern from crown | Summer | Pre-emergent spring; quinclorac seedling |
| Goosegrass | Silver-white crown, flat zipper pattern | Summer | Pre-emergent; post-emergent difficult |
| Foxtail (Yellow/Green) | Bottle-brush seed head, flat blades | Summer | Pre-emergent; quinclorac |
| Annual Bluegrass (Poa annua) | Light green, early seed heads, fine texture | Fall – spring | Fall pre-emergent critical |
| Dallisgrass | Tall clumps, long seed head, thick stems | Summer | Hard to control; MSMA where legal |
| Tall Fescue clumps | Wider blades than surrounding grass | Year-round | Dig out clumps; glyphosate spot treatment |
| Quackgrass | Waxy leaves, aggressive rhizomes, auricles clasp stem | Spring – fall | Very difficult; glyphosate spot treatment |
| Bermuda (in cool-season lawn) | Gray-green, stolons and rhizomes | Summer | Fenoxaprop; glyphosate spot treatment |
| Nimblewill | Fine blue-gray blades, thin-bladed grass | Summer – fall | Tenacity (mesotrione); multiple applications |
Sedges and Rushes Quick Reference
| Weed | Identification | Season | Control |
|---|---|---|---|
| Yellow Nutsedge | Triangular stem, V-shaped leaves, yellow flower | Summer | Halosulfuron-methyl (Sedgehammer) |
| Purple Nutsedge | Triangular stem, dark purple seed head | Summer | Halosulfuron; more difficult than yellow |
| Green Kyllinga | Mat-forming, triangular stem, greenish seed head | Summer | Halosulfuron; difficult |
| Path Rush | Rounded stem, green narrow leaves, drainage issue | Summer | Fix drainage; non-selective herbicide |
The Three Weed Categories — Why They Matter
Broadleaf weeds are dicots — they have two seed leaves at germination and typically grow with netted leaf veins. Their leaves are usually wider than grass blades. Dandelion, clover, plantain, ground ivy, and most garden weeds fall into this category. Selective broadleaf herbicides (2,4-D, dicamba, triclopyr, MCPP) kill broadleaf weeds without damaging lawn grass.
Grassy weeds are monocots like desired lawn grass. They have parallel leaf veins, narrow blades, and distinctive growth patterns that often resemble the surrounding lawn. Crabgrass, goosegrass, foxtail, and annual bluegrass are the most common. Broadleaf herbicides don't touch them — you need specific grass herbicides (quinclorac, fenoxaprop, sulfosulfuron) or pre-emergent prevention.
Sedges are a separate plant family — not grasses, not broadleaf weeds. The defining feature is a triangular stem (run your fingers along the stem; you'll feel three sides). Nutsedge and kyllinga are the main lawn problems. Standard broadleaf and grassy-weed herbicides don't kill sedges — you need a sedge-specific product like halosulfuron-methyl (Sedgehammer).
Using the wrong category of herbicide is the most common weed-control mistake. Broadleaf herbicide on crabgrass wastes money. Grassy-weed herbicide on dandelions wastes money. Identify first, then treat.
Seasonal Weed Patterns
Winter annuals germinate in fall and grow through winter: henbit, chickweed, annual bluegrass (Poa annua), hairy bittercress. They're most visible in early spring before dying off in heat. Control: fall pre-emergent herbicide is the critical application.
Summer annuals germinate in spring and die at first frost: crabgrass, foxtail, goosegrass, spotted spurge, spotted knotweed. They're most visible in mid-summer. Control: spring pre-emergent herbicide when soil reaches 50–55°F.
Perennials live multiple years and regrow from roots or rhizomes: dandelion, clover, plantain, ground ivy, wild violet, nutsedge, quackgrass. Control: post-emergent herbicide with fall treatment being most effective for most perennials.
Cool-season perennials are active in cooler weather: Poa annua (biennial in most zones), wild violet, ground ivy. Warm-season perennials thrive in summer: nutsedge, Bermuda (in cool-season lawns), nimblewill.
Identification Tips
Look at leaf shape first. Wide, netted-vein leaves = broadleaf. Narrow, parallel-vein blades = grass or sedge. Triangular stem = sedge.
Examine the growth habit. Rosette (leaves radiating from central crown): dandelion, plantain, thistle. Stolons (runners above soil): clover, ground ivy, creeping charlie. Rhizomes (underground runners): quackgrass, wild violet, Bermuda. Bunchgrass (clump from single crown): crabgrass, tall fescue clump, dallisgrass.
Check the season. If it appeared in April and flowered yellow: likely dandelion or yellow woodsorrel. If it appeared in July with wide blades in the sidewalk edge: likely crabgrass. If it's a low mat in a wet shaded area: likely ground ivy or creeping speedwell.
Use a phone plant-ID app as a starting point. Google Lens, PictureThis, iNaturalist, and Seek by iNaturalist all identify common lawn weeds with reasonable accuracy. Cross-reference the app's suggestion with the descriptions here before deciding on a herbicide.
When in doubt, your state's land-grant university extension service has regional weed-identification guides with photos. Purdue, NC State, Clemson, Texas A&M, Michigan State, and UC Davis all publish free online identification references tailored to their region's specific weed pressure.
Control Strategy by Weed Category
For broadleaf weeds: selective herbicide (2,4-D + MCPP + dicamba combinations) in fall applied at label rate. Fall treatment kills perennials by translocating herbicide to roots. Spring treatment is a distant second choice. Spot-treat isolated weeds with a tank sprayer; blanket treatments waste product on clean lawn areas.
For grassy weeds: pre-emergent prevention is the primary strategy. Prodiamine or Dithiopyr applied when soil reaches 50–55°F prevents crabgrass, goosegrass, foxtail, and annual bluegrass. Post-emergent quinclorac works on young seedlings but has limited value on mature plants.
For sedges: halosulfuron-methyl (Sedgehammer Plus) is the standard homeowner product. Apply in summer when sedges are actively growing. Multiple applications often required for nutsedge — yellow nutsedge responds in 1–2 treatments, purple nutsedge takes 2–3 sequential seasons.
Cultural prevention applies to all categories: dense, properly-fertilised, correctly-mowed lawn outcompetes most weed seedlings. Thin stressed lawns invite weed pressure regardless of herbicide programme.
Frequently Asked Questions
What kills all weeds but not grass?
No single product kills every weed category. Broadleaf herbicides (2,4-D + dicamba) kill dandelions, clover, and plantain but not crabgrass. Quinclorac kills crabgrass and some broadleaf weeds but not dandelions at effective rates. Halosulfuron kills sedges but nothing else. The right approach: identify the weed, then choose the matching product category.
How do I tell crabgrass from tall fescue?
Crabgrass has wide flat blades in a star pattern radiating from a central crown. Tall fescue grows vertically with blades up to ⅓ inch wide but emerging from the base at a consistent pattern, not star-shaped. Crabgrass is lighter green and appears in summer; tall fescue stays visible year-round in cool climates. Crabgrass dies at first frost; tall fescue overwinters.
What's the difference between crabgrass and goosegrass?
Crabgrass has a green crown and wider flat blades spreading outward. Goosegrass has a distinctive silver-white crown and flatter, more ground-hugging growth. Goosegrass thrives in compacted soil; crabgrass in regular soil. Both are controlled by the same pre-emergent products, but goosegrass is more difficult to kill post-emergent.
Are all three-leaflet plants clover?
No. Oxalis (wood sorrel) has three heart-shaped leaflets and looks similar to clover but has yellow flowers and a sour taste. Black medic has three leaflets but yellow clover-like flowers. True clover has white or pink flower heads. The distinction matters because oxalis is harder to kill than true clover — use triclopyr for oxalis.
Why can't I use Roundup on lawn weeds?
Glyphosate (Roundup) is non-selective — it kills every plant it contacts, including your lawn grass. Use selective herbicides designed for lawns: broadleaf products (2,4-D + dicamba) for dandelions and clover, grass-specific products (quinclorac) for crabgrass, sedge-specific products (halosulfuron) for nutsedge. Reserve glyphosate for driveway cracks, mulch beds, and pre-sod renovation.
About the Author
Lawn Care Expert & Writer · Denver, Colorado · Florida State University
Jason Allen is a lawn care expert and freelance writer based in Denver, Colorado. He studied turfgrass science and horticulture at Florida State University before founding his own lawn care operation serving the Denver metro area. With over a decade of hands-on experience managing cool-season lawns in Colorado's challenging high-altitude climate, Jason specializes in aeration, fertilization timing, drought management, and water-restriction compliance. His practical, science-backed approach to lawn care has helped thousands of homeowners achieve healthy turf despite Colorado's short growing seasons, clay soils, and frequent drought conditions.