Grassy weed identification and means for eradication
Can u please identify this aggressive plant? From one patch a few years ago it has expanded quickly especially this year. I noticed the pinkish color at the base of its stem which is similar to crabgrass but it grows vertically and when a large area is cut it resembles tall fescue except it is more limey than dark green. As u can see it grows additional leafy shoots in the main stem. The first photo is about a square foot, the second about two square feet and the last is an individual sample several inches in width as opposed to the group shots which cloak their more weedy intentions.
This is called roughstalk bluegrass (Poa trivialis). It is challenging to deal with since it cannot be controlled effectively by any selective herbicides currently on the market. See our website for further information. https://extension.umd.edu/hgic/topics/roughstalk-bluegrass
If you want to get rid of it and have a uniform lawn, you would have to renovate the entire lawn and re-seed. Keep in mind that even with a renovation, it is possible for Poa trivialis to return if there is an established seed bank in the soil or if seeds are brought in through seed mixes or outside equipment.