This forked grassy weed has choked out most of the grass in my lawn this summer. It doesn't grow very fast vertically but it seems to spread aggressively and densely.
does anyone know what it is? I live in Western PA (Zone 6A).
Pictures would help but it's probably crabgrass.
That is crabgrass!
There is a picture. I'm assuming you can't see it for some reason. Here's a direct link to the image:
I don't think it's crabgrass unless there are multiple types. The crabgrass that I am familiar with has wider blades then regular grass and grows out from a central point in big clumps, and is bright green. This is not like that - it is many individual center stalks growing very closely together. The blades are smaller then normal grass, and darker green in color.
I have done some more researching and I now believe this is Creeping Bentgrass.
Creeping bentgrass is second to crabgrass for cool season grass problems. Still, we hardly hear about it here.
If you decide you want to keep it, it makes an excellent turf. It likes to be mowed very low. One alternate lawn I've seen that worked very well was to seed Dutch white clover everywhere with the creeping bent. With that mix you will always have lush coverage, good weed protection, and never need to fertilize. You will also have lots of bees and you'll have grass stains if you skid around on the clover.