Crabgras an grow on a bowling ball in airless rooms, and there is no known way to kill it that does not involve nuclear weapons.
Guess what I did today.
Bet you sat in the shade sipin" slurpies!
Contemplating how to nuke crabgrass?
I've read that crabgrass is an annual, but it spreads so quickly I've never been able to determine the age of any single plant.
Anyway, what I wanted to tell you is that if you use CGM (corn germ meal) on the lawn to get rid of dandelions and other aggravating annual weeds, a side-effect is that the crabgrass does seem to diminish. It took 3 years for my lawn to become totally free of dandelions, and it's been several years ago since I first celebrated having a green lawn without yellow dandelions or other weeds.
Please note that CGM is a pre-emergent, meaning that it prevents seeds from sprouting, which is why it's commonly spread in the early spring. In my dandelion battle, I spread it at forsythia-showing-yellow-buds, 3 weeks later and another 3 weeks later. Is it expensive? Sort of. Compared to doing nothing, your wallet will definitely feel the price tag. Compared to using herbicides (as you know, they aren't very effective in spite of the advertising claims), CMG is only slightly more costly, and cheaper yet if you count honestly all the times you have to re-apply the ineffective herbicides. It's definitely cheaper than paying for the doctor's treatment of the knee I re-dislocated while getting up from a weed-pulling session.
I think the "pre-emergent" products are great and I've been using them for years and they work, and in my mind they are worth their weight in time spent pulling weeds.
There is a company called "Green" something or another that comes around in the neighborhood and is pushing their "no weed" service and charging a lot for the service.
I buy a box of pre-emergent and toss it around the grass and some weedy areas in my garden.
I used that CGM once and lo and behold: the quail and the ducks loved it, gobbled it all up.
I finally gave up using water and resources, I have, in winter and spring, a green patch and in summer it is a brown patch. I am lucky I can do that, no rules except my own on this place.