Offensive lime-green grassy plant
I hoping to ID and eventually eliminate (by appropriate means) a grassy plant that is taking over my four year old lawn of tall turf-type fescue. I have attached jpg photos. The pix of the single ‘stock’ of grass (PG_martin #3) is that of a piece pulled from the clump also attached. These pictures were taken on 23 April which was five days after the last mowing with the cut height on my Toro mower set to its highest setting, about 4 inches. The offending plant, which is very noticeable by its light lime-green color against my dark green fescue, has grown rapidly since last year when I dug up about four clumps. It has since taken hold in a previously unaffected section of my front lawn, but so far, not in my back yard. I used the same seed last October to seed both the front and back yards after aeration. I would greatly appreciate your help in identifying this plant and your suggestions as to how to eliminate it.
This looks like poa trivialis, a grassy weed that is very hard to eliminate. Click here for the lowdown: http://extension.umd.edu/hgic/roughstalk-bluegrass
Since you do not have too much yet, you may want to hand dig the clumps. Try to prevent it from going to seed and then mowing. It seeds prolifically and early.