Roughstalk Bluegrass: a Cool Season Perennial Grass

The blades are rougher, containing fine hairs, and a lighter green color than the other cool-season lawn grasses. This makes it an unwanted lawn grass. Also, roughstalk bluegrass is not drought tolerant, so it quickly turns reddish-brown when the soil dries. A positive characteristic of this species is that it is shade tolerant. Thus, it can provide cover for shaded areas where there is a demand for a lawn. Roughstalk bluegrass will stay green during the winter months.

The lighter green color and non-drought tolerance of roughstalk bluegrass make this grass unwelcomed in athletic fields and golf courses. Photo: Pete Landschoot, Penn State

Roughstalk bluegrass reproduces primarily by stolons, although it also produces seeds, which are the primary method for distribution to new areas. Similar looking species include creeping bentgrass and other bluegrass species. Roughstalk bluegrass and bentgrass both produce stolons. However, roughstalk bluegrass has folded leaves at the bud, whereas bentgrass has rolled leaves. Compared to Kentucky bluegrass, it has a lighter color, and the "boat-shaped" blade tips are more pointed. Also, Kentucky bluegrass does not produce stolons.

Poa trivialis reproduces primarily by stolons, a creeping horizontal plant stem or runner that takes root at points along its length to form new plants. Photo: Pete Landschoot, Penn State

Physical removal with a shovel or sod cutter is an option if the area is not too large. Herbicide options include the pre-emergent bispyribac-sodium (Velocity, which is the only selective material that can be used to remove roughstalk bluegrass from desired species, only registered for golf courses and sod farms). For isolated and small patches, glyphosate (non-selective) can be used and then the area(s) reseeded. If the population is substantial, then a complete renovation should be considered. Remember to always read the pesticide label for proper application sites and rates.