Crabgrass vs Nutsedge

Both weeds invade lawns in summer, and nutsedge is often called nutgrass, but it is not a grass at all. Nutsedge is a perennial sedge that spreads by underground tubers, while crabgrass is a summer annual grass that spreads only by seed. Knowing which one you have saves a wasted treatment.

Telling them apart matters because the controls are different. A preemergence product is timed before crabgrass seed germinates, while nutsedge is treated when it is visibly growing with 3 to 8 leaves. Look at the stem shape, leaf arrangement, color, and where the weed grows. Nutsedge likes wet, poorly drained soil, and crabgrass likes thin, sunny, bare turf.

Crabgrass vs Nutsedge side by side

Last verified October 2026. Typical values; individual animals, products and local prices vary.

When you are looking at which

Crabgrass

• The weed lies flat in a rosette with stems rooting at the nodes.
• You see 3 to 5 finger-like seed spikes radiating from the top.
• It sits in thin turf or bare spots and dies after the first frost.
• Leaf blades look like ordinary grass blades, flat and not V-shaped.

Yellow nutsedge

• A stem rolled between your fingers feels three-sided and does not roll round.
• Leaves come in sets of three and stand taller and stiffer than the lawn.
• The patch is yellow-green and shiny, in a wet or poorly drained part of the yard.
• Pulling it leaves small tubers in the soil, and it returns in the same spot.

How this works

The quiz counts which answers fit crabgrass or yellow nutsedge. Stem shape and leaf arrangement are the strongest cues, while site, color, and seedhead timing support them. Answer only what you checked, and use I can't tell for the rest, since a skipped cue should not decide the result.

It covers smooth and large crabgrass and yellow nutsedge. Purple nutsedge, kyllinga, and other grass weeds differ, so a close result may need a local extension office. A tie means your answers were split, and rolling the stem between your fingers settles it in seconds.

Where these numbers come from

The figures and defaults on this page are based on:

• Penn State Extension: Yellow Nutsedge, Three-sided stem, tubers, wet soils, and herbicide timing. (checked October 2026)
• Penn State Extension: Smooth and Large Crabgrass, Summer annual, V-spikes, germination temperature, and mowing. (checked October 2026)
• UC IPM: Yellow Nutsedge, Triangular stems, leaves in threes, tubers, and seedhead. (checked October 2026)
• University of Maryland Extension: Crabgrass, Prostrate stems rooting at nodes, germination, and mowing height. (checked October 2026)

Weed-identification guide. Follow herbicide labels and local extension recommendations for your lawn.