Don't waste the Atrazine. Atrazine may damage certain cultivars of Bermuda during Spring, but it is a common part of Bermuda lawn programs in the southeast to control Annual Bluegrass during winter dormancy. What's more, the image looks more like a common Bermuda, which is less likely to be effected by Atrazine. If it is a small area, and you won't to avoid having it increase in size, use a product like Fusilade II. Fusilade II is used around ornamental landscapes and Liriope beds to kill Bermuda selectively and quickly. It works better than Round up at killing Bermuda, but is likely to damage the St. Augustine as well. So there again, it really depends on how far it has spread. Also, if you go that route, wait until the Bermuda has fully transitioned and again expect what ever St. Augustine is sprayed to die initially, and then fill back in from the surrounding turf. Here is a link that might be useful: Serenity Lawn Service

You could try protecting the "good" grass surrounding the clumps by wrappinig some plastic around the base of the stuff you're trying to kill and then spraying it. With Glyphosate all you need to do is mist down the foliage which will then carry the herbicide to the roots and kill it. I've found mixing in a little dish detergent with the glyphosate helps it stick to the leaves better. You're still going to end up with a bare spot where the weed was. When did you reseed the lawn (time of year)? And what type of seed did you put out?

Tamelask, I'll try to get a better shot today, the conditions are a little better for photography. Maybe I can get a clearer pic for you. Alicia, thanks for your input, I do have a lot of butterflies here. I see them contstantly. John, LOL not bare dirt. The picture is taken where there is a backdrop of two areas I didn't seed on purpose for a bed and patio area.The area is at the edge of the lawn. I put in Bermuda which is only starting to come out of dormancy now. Considering the conditions this poor lawn has endured since it was planted, I'm not too disapointed in it. I completed my house Feb. 07. put in the seed in 4-07 and had to fight with drought and water restrictions all year. I didn't put any winter Rye in because of the water it needs and because of the new Bermuda. From my research, I understand it's not great to put Winter Rye in on a brand new Bermuda lawn. I'll upload a series of pics from last year and the planting/growing process if you wish to see them. I know the grass will eventually out compete, however I want to make sure I don't have something starting that is exceptionally tough. Right now this stuff is everywhere!! This is one of the reasons I chose Bermuda for it's ablity to "choke out" weeds. :-)

I have some of this stuff (whatever it is) in my back yard where I dug out a post that was sunk in concrete. After I dug out the concrete, I filled it with dirt. It's left about a 2' circle of bare dirt. This stuff germinated from some weeds seeds I guess. As the bermuda spreads to cover, it's crowding this stuff out. Mow often, mow low, fertilze once a month & it'll make it's way outta there. (PS. the only reason I think this stuff germinated there is due to all the rain we've had here in Oklahoma the last several weeks. I've had measurable rain at my house now for the last 20 straight days! Once we get back to the normal Oklahoma hot dry weather & I'm back to only watering twice a month, while mowing every 3rd day, my lawn is so dense virtually NO weeds survive.) Good day, Dan