DuckSouth.com

What can I spray to kill crab grass in my lawn?

What species of grass is your lawn made up of? That's pretty important.

Sorry, it's centipede grass.

bigoak wrote:Sorry, it's centipede grass.

Gotcha. I'm no expert, but just operating off of what I've read and from a buddy who recently started his lawn over with centipede. He spent a lot of time after watering his lawn just walking around and pulling the stuff.

Pre-emerge is the main control. Don't think there is going to be any selective post-emergent herbicides you can use, but could be wrong.

Also, keeping the yard mowed low will select for the centipede as it will thicken with runners close to the ground. Cutting low will keep the crabgrass from developing seed-heads and getting much leaf area.

Wait to hear from others, but that what I've got.

Atrazine or imazapyr.

You have several options, but good luck finding them:

sulfentrazone + prodiamine mix (Pre-emerge and early post-emerge control - use lower rate for centipede)
DCPA (pre-emerge)
flazasulfuron (post-emerge)
dithiopyr (pre-emerge)
pendamethalin (pre-emerge)
bensulide (pre-emerge)

Atrazine can only provide limited control of crabgrass. It is meant to target broadleaf weeds.

I think I would check the label before using imazapyr on my lawn.

Warm winter + wet summer= lots of crabgrass. I wouldn't worry about it this late in the game. Preemerge next year.