What does crabgrass mean?
Crabgrass is a common noun referring to a group of coarse, fast-spreading annual grasses belonging to the genus Digitaria, most notoriously large or hairy crabgrass (Digitaria sanguinalis). These plants germinate in late spring, form low, sprawling mats that resemble a crab's splayed legs — the source of the common name — and produce enormous quantities of seed before dying off at first frost. Because it thrives in thin, bare, or drought-stressed turf, crabgrass is among the most familiar and most disliked lawn weeds in North America, prompting a whole industry of pre-emergent herbicides and cultural controls aimed at keeping it out. The word is used almost exclusively in gardening, agriculture, and lawn-care contexts and carries an unmistakably negative connotation; it also appears figuratively to describe anything tenacious and unwelcome. In British English the same grasses are usually identified by the genus name Digitaria rather than called crabgrass.
nounA coarse, spreading annual grass of the genus Digitaria, especially D. sanguinalis, that grows rapidly in lawns, gardens, and disturbed ground and is widely regarded as a troublesome weed.
- Any weedy annual grass of the genus Digitaria, particularly hairy or large crabgrass (Digitaria sanguinalis), notorious for invading lawns and gardens.
"No matter how carefully he tended the lawn each summer, crabgrass always crept back along the edges of the driveway."
"The bare patch left by the removed shrub was quickly colonized by crabgrass."
"Gardeners are advised to apply pre-emergent herbicide in early spring before crabgrass seeds germinate."
The plural is uncommon because crabgrass is usually discussed collectively as a single nuisance; it appears mainly in botanical or agricultural writing referring to several species of Digitaria.
"Warm-season turf in the Southeast must contend with several crabgrasses, including smooth and large crabgrass."
Crabgrass got its name from the way its stems sprawl low across the ground like a crab's legs — and it can produce tens of thousands of seeds from a single plant.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of crabgrass
Crabgrass is a compound of 'crab', from Old English 'crabba' and related to similar words in other Germanic languages such as Dutch 'krab' and German 'Krakbe'/'Krabbe', combined with 'grass', from Old English 'græs'. The name arose because the plant's prostrate, many-branched stems spread outward from a central point like the legs of a crab. The compound has been in use since at least the late sixteenth century in English botanical writing, when European naturalists were cataloguing the world's grasses.
How crabgrass is actually used
Crabgrass carries a strongly negative connotation in gardening and lawn-care contexts, where it is a byword for unwanted, invasive growth. The word is chiefly North American in everyday use; in British English such grasses may be referred to more generally by their scientific name or as 'Digitaria' or 'finger grass'. It is occasionally used figuratively to describe something persistent and unwelcome.
Easily confused with crabgrass
Quackgrass is a perennial creeping grass (Elymus repens) with underground rhizomes, whereas crabgrass is an annual Digitaria species that spreads by seeds above ground.