Turfgrass Weed Library

Large crabgrass is the most widespread annual grassy weed in managed turf. A single plant can produce 150,000+ seeds. It germinates when soil temperatures reach 55°F at a 1-inch depth, exploiting thin or stressed turf. Dies with first frost but leaves bare areas vulnerable to erosion and re-invasion the following year.

Goosegrass is a summer annual grassy weed tolerant of compacted soils and low mowing heights. It germinates 2–3 weeks later than crabgrass, making timing of pre-emergent applications critical. Its prostrate, star-like growth habit gives it high tolerance to close mowing on golf courses and athletic fields.

Yellow nutsedge is a perennial sedge that spreads via underground nutlets (tubers) that can remain viable in soil for several years. It outpaces most turfgrasses in summer heat, growing 2–3 times faster than surrounding turf. A single plant can produce hundreds of nutlets in one season, making population control difficult once established.

Dandelion is the most recognized broadleaf weed in cool-season lawns. Its deep taproot (up to 10 inches) stores energy reserves, making hand-pulling ineffective unless the entire root is removed. Each plant can produce hundreds of wind-dispersed seeds. While not highly competitive with healthy turf, large populations indicate low nitrogen or other turf stress.

Annual bluegrass is simultaneously one of the most challenging and most complex turfgrass weeds. On golf course greens it is tolerated or actively managed as part of the playing surface; in other settings it is an invasive weed that dies in summer heat, leaving unsightly bare patches. It produces seed heads continuously — even under close mowing — and can set seed within days of germination.