Bermuda Grass vs Crabgrass: How to Tell Them Apart
Bermuda grass and crabgrass are frequently misidentified because they share several surface-level characteristics: both are fine-to-medium-textured grasses that spread by horizontal runners, both grow vigorously in summer heat, and both are lighter green than many turfgrasses. Misidentifying established Bermuda grass as crabgrass leads homeowners to apply herbicides that damage desirable turf, while misidentifying crabgrass as Bermuda delays treatment and allows the weed to set seed. The differences between them are clear once you know what to look for.
Side-by-Side Identification
Bermuda Grass (Cynodon dactylon)
Growth habit: A perennial warm-season grass that returns from the same root system every year. Goes dormant in winter and greens up again from established crowns, rhizomes, and stolons in spring.
Leaf texture and color: Fine to medium texture with narrow leaf blades. Deep green to gray-green color during active growth. Blades have a distinctive two-row arrangement along the stem (distichous arrangement).
Stems: Stolons (above-ground runners) are wiry, tough, and rooted at nodes. The stems are round in cross-section and branch frequently, creating a dense interlocking network on the soil surface. Stems have a distinctly wiry feel when handled.
Seed heads: Three to seven finger-like spikes radiating from a central point, often described as a bird’s foot or hand pattern. Appear at various times during the growing season.
Ligule: A fringe of fine white hairs (ciliate membrane) at the junction of the blade and sheath. This is a reliable microscopic identification feature that distinguishes Bermuda from crabgrass.
Behavior in fall and winter: Turns brown and goes completely dormant as temperatures drop below 55 degrees Fahrenheit. Returns in spring from the established root system.
Crabgrass (Digitaria spp.)
Growth habit: A summer annual that germinates from seed each spring when soil temperatures reach 55 degrees Fahrenheit. Killed by the first frost and does not return from roots. Must regrow from seed the following season.
Leaf texture and color: Medium texture with wider leaf blades than Bermuda grass. Light green to yellow-green color, noticeably paler and more yellow than Bermuda.
Stems: Stems are lower-growing and more sprawling than Bermuda. Nodes are visible along the stem and the stem often has short hairs. Less wiry than Bermuda; crabgrass stems feel softer.
Seed heads: Multiple finger-like spikes (4 to 13) radiating from a single point, resembling the toes of a crab. Seed heads are larger and more prominent than Bermuda seed heads. Appear in mid to late summer as the plant sets seed.
Ligule: A flat, membranous ligule (not hairy) at the blade-sheath junction. Distinctly different from Bermuda’s hairy ligule.
Behavior in fall: Crabgrass turns purple-red before dying completely with the first frost. It does not go dormant; it dies.
The Fastest Visual Tests
When you spot a spreading, light-colored grass in your lawn, apply these quick checks before reaching for an herbicide:
1. Pull on a stem and check resistance. Bermuda stems are tough and wiry and require effort to pull out. Crabgrass stems pull more easily and feel more pliable.
2. Look at the color. Bermuda grass during active growth is darker green than crabgrass. Crabgrass has a distinctly lighter, often yellow-green appearance.
3. Look at the seed head shape. Both have finger-like spikes radiating from a central point, but crabgrass typically has more fingers (4 to 13) and the overall seed head is larger and more open-branched.
4. Check the season and conditions. In early spring, what appears in dormant lawn areas is almost certainly Bermuda grass greening up from established rhizomes and stolons. Crabgrass does not appear until soil temperatures have consistently exceeded 55 degrees Fahrenheit, typically late spring at the earliest.
5. Does it survive winter? If the spreading grass returned in the same location from last season without reseeding, it is almost certainly Bermuda or another perennial grass. Crabgrass must regrow from seed each year.
Why the Misidentification Matters
Applying a crabgrass pre-emergent to Bermuda grass does not kill the Bermuda because pre-emergent herbicides only affect germinating seeds, not established plants. The pre-emergent window passes, and nothing happens to the Bermuda.
Applying post-emergent grassy weed herbicides (quinclorac, fluazifop) to Bermuda grass, however, can damage or kill established Bermuda because these active ingredients affect living grassy tissue indiscriminately. Homeowners who apply post-emergent crabgrass killers to what they thought was crabgrass sometimes damage large patches of their Bermuda lawn.
If you are uncertain which grass you are dealing with, use the identification tests above before treating. When in doubt, take a close-up photo to your local cooperative extension office for identification assistance.
What to Do With Each
If it is Bermuda: Leave it alone if it is growing where you want lawn grass. If it has spread into beds, use non-selective glyphosate applied carefully with a foam brush to treat individual stems, or use a selective grass killer (fluazifop-p-butyl) specifically in bed areas.
If it is crabgrass: Apply a post-emergent herbicide containing quinclorac or fluazifop-p-butyl on young plants. Apply a pre-emergent herbicide (pendimethalin, prodiamine) the following spring before soil temperatures reach 55 degrees Fahrenheit to prevent the next generation. See how to use pre-emergent herbicides on your lawn for timing and product guidance.