This troublesome weed has been causing nightmares for homeowners, golf courses, sod producers and sport field managers alike. Even so, this annual invasive species of Eurasian bluegrass isn’t the only reason for pre-emergent treatments in warm-season lawns.

You’ve Seen Poa Annua And Probably Didn’t Even Know It

It forms the large dead patches of yellow mat in your summertime lawn. This annual grassy weed will aggressively compete with other more desirable plants for both lawn and garden space.

Lawns And Grasses Fall Into Two Categories

Grass for more northern climates are considered “cool season” species, while grass better suited to Georgia’s southern turf are “warm season” species.

Warm season grasses are slower to germinate and to establish themselves during the initial growing season when compared to grassy weed species. This means Poa annua, crabgrass, goose grass and barnyard grass are problem weeds as the seeds will germinate in the spring, grow throughout the summer, produce and distribute seeds, and die off at the onset of cold weather.

Weed control begins with proper lawn care and management. You want a healthy, dense turf. A thick turf in and of itself will lessen the invasion of grassy weeds, as root space is not available for those ready to grow weed seeds.

Your Best Weapon Against Poa Annua, Crabgrass And Other Grassy Weeds

poa annua a serious weed in a lawn

Pre-emergent lawn treatments are most effective in controlling annual grass weeds like crabgrass, goose grass and Poa annua (European walkgrass). It is applied to the soil before weed seed germination and will be absorbed by the newly germinated young roots and shoots as they grow.

Annual grass weeds will invade lawns, be unpleasant to look at by interrupting the uniformed appearance of your lawn, and will be unpleasant for barefoot walking. Grassy weeds are fierce competitors and will steal important soil nutrients and water, and tend to be prolific seeders. And these grassy weeds will be among the first plants to grow in a cleared or recently-disturbed soil area like your garden beds.

Non-Native Invasive Poa Annua

Poa annua will form large mats during the cooler months from fall to spring, but its high production of seeds and yellow die-off will look awful during the heat of summer. As an annual, Poa annua will complete its life cycle in one growing season. Texas A&M University found that one plant will produce more than 350 viable seeds in its lifetime, and these seeds can remain dormant for years. Michigan State University believes no other grassy weed adapts to a variety of conditions like Poa annua.

Homeowner Tips For Controlling Problem Grassy Weeds

  • Mowing: Cut your grass at the higher recommended length, so the lower Poa annua will be ‘starved’ for sun and will produce fewer seeds. Cutting the grass at a higher setting will also encourage a dense and healthy stand.
  • Fertilizing: Keep your lawn well fed. Healthy turf with dense root systems will prevent pest grass seeds from germinating, but only at the proper time and strength. You’ll want to do a pH soil test to determine the proper lime application.
  • Watering: Water your lawn at the first signs of drought. This ensures a healthy root system. Water as needed depending upon the weather.
  • Patch removal: Keep your lawn free from minor grassy weed clumps by digging up the plant. Make sure that you dig a couple of inches around the grass and lift from underneath to get its root system too. Burn the plant and seeds. Cover the bald area with plastic (stake down or lay stone/bricks around the edges) for about 4 to 6 weeks.
  • Spot treat with pre-emergent applicants: Walk around your lawn and look for grassy weed patches. Apply a pre-emergent herbicide in the fall and spring to prevent the grassy weed seeds from germinating.

When in doubt, contact your lawn care specialist for testing and effective pre-emergent application to keep your lawn beautiful and barefoot-friendly all season long.


  1. Texas A&M University:
  2. Michigan State University: