Question
I live on the central coast of CA and have some Kentucky Blue grass in the front yard. At least I think thats what it is. Its a finer variety than the more standard "Enduro" grass. Anyhow, Ive got some sort of fine-bladed crab grass invading quickly. I tried to kill it off by snipping tops off and carefully dabbing on Round Up to no avail. It is spreading fairly fast and goes dormant in the winter here leaving dead spots amongst the desired lawn. Is there any way to get rid of this? Thanks.

Answer
'Central Coast', the Monterey County environs -- officially that covers everything between Point Mugu to Morgan Hill.  Guessing from my basic geography (this is where zipcodes help) you have... a Mediterranean climate?  

University of California at Davis posts an online Weed Identification Guide for your viewing pleasure:

http://www.ipm.ucdavis.edu/PMG/weeds_common.html

Please view their photographs of Italian Ryegrass, Perennial Ryegrass, Quackgrass, Bermudagrass, Annual Bluegrass, Littleseed Canarygrass, Southwestern Cupgrass and Prairie Cupgrass, and confirm that one of these is your queried Weed -- or not.  There are also photos of Crabgrasses, but their wide blades do not match your description of this invader as 'a finer variety'.

If you would like to supply your zipcode, I'll be happy to send you contact information for your local Cooperative Extension agent; they are very good at accurately identifying Weeds.  

Depending on what this particular Weed is, you can take measures to eradicate it, anything from setting your mower height to prevent seed production to solarizing for complete removal of all green life next Summer.

It would also be helpful to identify, with certainty, your Turfgrass type.  Different Lawngrasses have different needs; why treat yours like Bluegrass if you are growing Paspalum or Zoysia?

Thanks for your note, please RSVP...