Crab grass - its taking over my lawn!

[trele6]

What are the weeds that look dark green but shoot straight up out of one cluster which has 2-4 blades in it?

[haudi]

Nutsedge.

Originally Posted by trele6

What are the weeds that look dark green but shoot straight up out of one cluster which has 2-4 blades in it?

[trele6]

Originally Posted by haudi

Nutsedge.

Man those things are a pain also. I don't have issues with crab grass, but I have a side of my lawn that is covered in these and just cant get rid of them.

[DanielWayne]

I am clearing a frikin garden of nutsedge little by little each day. There is an underground root system that makes it impossible to kill by just pulling it up. Afterward I'm laying down newspaper and then mulch. That will prevent it from coming back for about a year, then must repeat.

[Transplanted99]

Originally Posted by haudi

Are you sure it's crabgrass and not nutsedge? Nutsedge is even worse because it can grow several inches tall in the span of a week making it look like you never mow.

That is exactly how it seems. The lawn is rather short and thick, so these guys really stand out.

Your photo looks like what I am talking about (both the weed and the lawn).

It started with only a few in a few sprigs here and there, and now it has some concentrated areas, and inch or two between each sprig it seems (but going from eyeball memory, might be a bit tighter than that).

The main lawn around it still seems quite healthy, but I'm sure it would eventually crowd it out.

Update: Read the article that holds the photo in the link you provided...it sounds exactly like the weed I see.
http://www.showcasegroup.biz/blog/nutsedge/

[HoustonBornNRaised]

I have a really strange grass taking over my backyard. It's super soft, with very thin blades, and it sends runners and pops up in my flower beds. When my backyard gets stressed due to the heat, it's the first to turn brown, but it comes back.

This is something that I've never seen before, and wasn't there until this year. We now have 10x10 patches of it. It's driving me crazy. My husband thinks the seed was brought in by the guy who mows our yard.

[Transplanted99]

Okay, did some research on products to use. Best summary I found was here: TurfMagazine.com - Proven Yellow Nutsedge Control Strategies

Pulling them now will be ineffective, as I read, since they can regenerate underground. Would work if only one or two, but too many now to do this. So, next option is herbicide.

From my reading on several other sites, the current most effective post-emergent (after they appear) treatment is with sulfentrazone (Dismiss, Dismiss South, or Image are examples) or with halosulfuron (Sedgehammer is an example).

Also, fyi for anyone reading this later...For pre-emergent treatment, I only found two sulfentrazone - based products (Echelon, and Dismiss - I presume Dismiss South too, but didn't research that out).

I read one university study that seems to indicate that halosulfuron is slightly faster acting, but both have similar efficacy after two months, and that both may require two applications.

I pulled the trigger on Sledgehammer...will let folks know the experience.

[haudi]

Transplanted - I use the Imagine spray that you hook up to a hose and it seems to work pretty well. It WILL turn your turfgrass a little yellow after the first application but it will come right back. This is the only way to kill this damn stuff.