The Quick Test
Pull a blade and look at the base where it meets the sheath. If you see two small finger-like projections (auricles) clasping the stem, it’s quackgrass. Crabgrass has no auricles. Also check the timing: if the patch appeared in the same spot as last year and was one of the first things to green up in spring, it’s quackgrass (perennial). If it appeared in a new location in late spring, it’s crabgrass (annual from seed).
Why This Matters
Crabgrass is preventable with pre-emergent and treatable with quinclorac. Quackgrass has no selective herbicide option and no effective pre-emergent because it’s already established underground. The treatment for quackgrass is spot-kill with glyphosate and reseed. Using crabgrass products on quackgrass wastes money and time.
