Rough Bluegrass is a perennial grassy weed that is also known as Roughstalk Bluegrass or by its scientific name, Poa trivialis. This lawn weed is known for remaining green throughout the winter.
Rough Bluegrass can be identified as a stolon-forming perennial grassy weed that bends at the base. This grass is considered to be a lawn weed because it is lighter in color than Kentucky Bluegrass or Perennial Ryegrass. It has a long ligule that is toothed at the tip. Its collar is smooth and broad, and its sheaths are compressed and rough to the touch. The blades of this lawn weed are flat, rough on the edges and taper to a “boat-shaped” tip. Rough Bluegrass plants may go dormant during the summer months but will remain green through the winter. This grassy weed often forms noticeable patches in home lawns.
Rough Bluegrass is a lawn weed that grows in a wide range of habitats throughout much of North America. These perennial grassy weeds can germinate and spread from seeds, but they also produce a root structure (tubers, bulbs or corms) that can birth new weeds from your lawn's surface (using stolons) or from underground (using rhizomes). Perennial grassy weeds live two or more years and have a deeper root structure that can give rise to new weeds—even if you no longer see the weeds in your lawn.
Much like Annual Bluegrass, there are no cultural control methods that can remove Rough Bluegrass, including hand-pulling lawn weeds or proper watering and mowing. However, there are currently no known selective weed control treatments that can control this grassy weed either.