Of your lawn is 99.9% crab grass you don't need read any further!
If your lawn is being visited by flocks of starlings, grackles or cow birds AND/OR has lots of 1/4-1/2" holes AND/or has brown patches get right on down to your nearest lawn supply and get grub killer. I used the Spectracide version with "restorer" aka fertilizer about a week ago after noticing all of the above to varying extents..
The summer season has been relatively mild and wet so lawns should be green and vibrant now.
Note: I also applied in the Spring but my routine is 2X per year as I would rather pay Lowes for grub killer than re-seed my lawn.
