Grass or Weed?
Hello! I have a patch of lawn that looks different from the rest of my lawn. Last year, I planted some dense shade grass seed here (since this area is beneath a large tree). I can't tell whether this patch is the dense shade grass or some sort of widespreading weed. I appreciate your advice and recommendations. Thank you!
This is poa annua (also known as annual bluegrass.) It is an annual weed. It seeds very quickly in spring, as you can see, and dies out over the summer. This explains what causes it and how to manage it: https://extension.umd.edu/hgic/annual-bluegrass Pay close attention to the environment that encourages it.
It may have come in in the seed mix, if you've never seen it before. Or it may have simply sprung up because the other grass is thin and it have little competition.