Roughstalk bluegrass

(More Lawn Weeds)  (Lawn Control Options)

Roughstalk bluegrass
Poa trivialis

(Photo credit: Perdue University Turfgrass Program: Turf tips 5/2008)
Lighter colored Poa trivialis in a darker tall fescue lawn

Life Cycle

Perennial, cool season grassy weed. 

Growth habit 

Forms light green patches that are evident early in the season. They can turn brown and go dormant in the heat of the summer. Grass blades can look shiny.

Reproduction

By seed and stolon(above ground runners) formation. Prolific seeder. 

Conditions that favor growth

Thrives in poorly drained, compacted soil, shade. Will move into sunny areas of the lawn. Spreads aggressively. 

Roughstalk bluegrass coming out of dormancy and beginning
to grow in early spring

Management

Cultural control: Maintain healthy, dense turf that can compete and prevent weed establishment.
Mechanical control: Small infestations can be dug out; must remove all parts of root. Then reseed. 
Chemical control: Perennial grasses growing out of place in lawns are extremely difficult to control selectively in turfgrasses. Cannot be effectively controlled by any of the herbicides currently on the market. Total lawn renovation or killing the patches using glyphosate and then reseeding will slow it down but because of the vast seed bank in the soil, it will return.