Roughstalk bluegrass
Poa trivialis
(Photo credit: Perdue University Turfgrass Program: Turf tips 5/2008)
Lighter colored Poa trivialis in a darker tall fescue lawn
Perennial, cool season grassy weed.
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.
By seed and stolon(above ground runners) formation. Prolific seeder.
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
Chemical Treatment in Lawns
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 (an ingredient in a non-selective herbicide) and then reseeding will slow it down but because of the vast seed bank in the soil it will return.
NC State Poa trivialis (good for identification)