Rough bluegrass is a perennial grass brought from Europe, named for its leaf sheaths, which feel like fine sandpaper when you run your fingers down them. It is now a common weed of lawns and golf courses across much of the US and Canada, where it forms light green, shiny patches in shady, damp spots. It's also called roughstalk bluegrass.
Appearance
- Growth form
- A cool-season perennial grass usually about 16–40 in (40–100 cm) tall, sometimes shorter or taller, that spreads by short aboveground runners (), forming patches.
- Leaves
- Shiny, pale green to yellow-green blades about ⅛–³⁄₁₆ in (2–5 mm) wide, folded in the bud, with rough edges and surfaces. The —the thin membrane where blade meets sheath—is usually long and pointed, about ⅛–¼ in (3–7 mm).
- Flowers
- An open, branching seedhead about 4–8 in (10–20 cm) long, much like Kentucky bluegrass, appearing from mid-May through June in the Midwest.
- Seasonal forms
- It often stays green through winter, but in summer heat the leaves turn purplish, then brown, and patches go dormant and look dead. The runners can resprout later.
Look-alikes
Where it lives
- Typical habitats
- Lawns and turf
- Wet meadows
- Stream banks
- Roadsides
- Range
- Native to Europe. Introduced to most of the continental US and Canada, including all six New England states; it is considered invasive in the Great Lakes region, where it was recorded as early as 1843.
- Preferred conditions
- Thrives in moist soil and shade, and often grows in wetlands, floodplains, and along streams. It handles drought and hot summers poorly.
- Flowering
Flowers May–Jun
Flowers May–Jun
Growing it
- Care
- Included in some lawn seed mixes for moist, shady spots, and sometimes used to overseed bermudagrass greens on golf courses.
- Propagation
- Spreads by seed and by runners. Its seed is a common contaminant in uncertified turfgrass seed, which helps it spread.
Conservation
- IUCN Red List
- NENot EvaluatedNot yet assessed
More species to explore
Record what you meet and build your own collection
Your photos are kept with their date and place, and you can fill regional albums one species at a time.