Rough Bluegrass is a cool season grass that does well in damp shady areas. Consequently, it thrives in our cool wet spring conditions, but turns brown and plays dead as soon as the weather gets warm.
Rough Bluegrass is a cool season grass that has recently become a big issue in lawns for two reasons. First, for environmental reasons, grass seed producers are no longer allowed to burn their fields and secondly, because rough bluegrass is very similar in size, shape, and weight to Kentucky Bluegrass. Since seed producers don’t burn their fields, they collect more rough bluegrass seed every year. Because the seed sorting equipment has a difficult time distinguishing rough bluegrass from regular bluegrass, rough bluegrass gets included in mixes. It appears frequently in Kentucky Bluegrass sod.
If you have small patches you can try digging it up and reseeding. You could also use glyphosate to kill it. If there is a lot, we recommend a complete lawn renovation. After renovating, you can keep it from coming back by seeding with a mixture that doesn’t have a lot of bluegrass, (so you reduce your risk of bringing in Rough Bluegrass) mowing high and watering infrequently.