In the lower AZ deserts, we use pre-em in February and August. Works well. I use a Lesco product.
 

For post-emergent control of crabgrass, your best option is Dimension Herbicide @ 2 apps of 1.5pt/acre, 6 weeks apart, or one full-page app of 48oz/acre. Dimension is also a great Pre-M.

quote:

Originally posted by paceac:
I've had the best success with pulling it manually. I haven't had much luck with sprays. It can be tough but trying to get the roots is key. Sometimes it is better to just dig out large patches and reseed with grass.

This method works for me as well.

quote:

Originally posted by lopezp:
For post-emergent control of crabgrass, your best option is Dimension Herbicide @ 2 apps of 1.5pt/acre, 6 weeks apart, or one full-page app of 48oz/acre. Dimension is also a great Pre-M.

Dimension is what local golf courses use and has worked for me.

To split hairs, I believe it's water grass, a crabgrass relative. Very dense and hard on mowers. It shows up after long wet periods, first appearing as kind of yellowish/green.

quote:

Originally posted by D_Steve:
I use this stuff, Ortho® Weed B Gon® Plus Crabgrass Control Concentrate2 ,
once the crabgrass shows up in the spring , again in the fall if needed.
If crabgrass is in the neighborhood uncontrolled you will always have it.

Ortho also makes the Weed Be Gon w/o the CG control. Make sure to use the one with it listed above.

Well the whole damn neighborhood doesn't care about their lawns, so I guess it'll always be an issue. My neighbors let their grass get knee high before they cut it. And they never weedeat so my fence lines always look like shit.

If you have neighbors in the area letting it go to seed, you're way behind the game. Crabgrass releases hundreds of thousands of seeds at a time & they are viable for years after.
Your best defense is a good offense (keep their team off the field....). Pre-emergent herbicides don't have to be selective (to not kill the good grass). I use one in the spring, when the ground temp is ~50* (sunny days are 70ish) spread w/dry fertilizer, then a liquid application in early may (days in low 80s). I also spray trimec for broadleafs at that time. I'm surrounded by corn/bean/melon fields, the edges of which are a breeding ground for all kinds of weeds.
Crabgrass doesn't germinate until the ground gets warmer - mid-May here- that's why you see it in full force in July/August. If you just put pre-emergent down early, it's washed away by spring rains. Weather was screwed up this year (Hot/dry May, wet June, Dry since) so my yard looks like hell, but my suggestion usually works.

quote:

If you have neighbors in the area letting it go to seed, you're way behind the game. Crabgrass releases hundreds of thousands of seeds at a time & they are viable for years after.

It's a never ending battle.
Pre-em every spring, weed-n-feed in summer.