Kevin, I used Image Nut Sedge killer earlier this summer on my Bermuda. It worked great with only one application. I've read on other forums that it works differently depending on the temperature so you may only see some yellowing on the first go-around and have to apply it again after about two weeks. I've been pretty happy with my results. I bought it at a big box store. All of the other solutions that I heard about were more expensive and harder to find. One caution, I probably sprayed it heavier than I should have. The Bermuda around it yellowed a bit for a couple of weeks but bounced right back. I have no idea how it will affect your KBG/Fescue. Maybe someone else can chime in.

Thanks jtyrie, i just read on their website its for warm season grasses, not sure if i should be using that?
http://www.amdro.com/Image/Nutsedge/index.html

Kevin, weed b good is ineffective and definitely no need to round up. SedgeHammer all the way! It is very effective, but as a fair warning, it will kill it, but it takes a while. You can order single use packages off of Amazon for less than 10 bucks. Buy 2 packs. It will kill the first time you spray it but there are probably a few plants that are too young to see or you will miss. One pack makes enough for 1000 sq ft, but the reason you need two is that the chemical becomes inert after a day. Let them grow for a bit so it sticks up above your grass, then hit them all with the sedgehammer. It will probably pain you to do so, but try not to mow for two full days later. ( I know, it is ugly). You won't notice it turn yellow for about 2 weeks, but you will notice right away that it stops growing. About two weeks later, mix up another batch and hit and new/missed green plants. Won't hurt to go over the yellow ones again too. One other thing, technically, you need a nonionic surfactant to put in the mix to break the surface tension of the water so it can better coat the plant. If you have a friend who is a chemist or in agriculture, ask him or her for it. You can buy it but it might a little expensive for you usage. Otherwise, you can just look at the ingredients of dishsoap and look for one that says it is a nonionic surfactant. Most are an ionic surfactant, though. In a pinch, I have used ionic and it has worked too, just not as well.

Thanks jdruding, is this stuff ok to use on cool season grasses? I read on their website to only use on the listed warm season grasses. Im not entirely sure what my type is, but i have some KBG/fescule and a patch of Zoysia.

It is safe for cool season grass. Check the link below for the label. I'm only a little south of you and have Galaxy KBG. (not sure if the galaxy in your name refers to the type of kbg you have ;-) )

Here is a link that might be useful: SedgeHammer label

Thanks! i just ordered 3 packs. Now seeing as 1 packet does 1000 sq ft and i dont need that much can i use say half of it with water? Or does it become inert as soon as i open the packet? Thanks for all the Help!!

Kevin, how would you characterize the area where the nutgrass is growing? Is it more of a low spot in the yard or a high area?

It comes as little beads in a little dissolvable plastic bag. I suppose you could cut open the bag and divide the beads in half. I think the clock only starts ticking when you mix it with water.

dchall, it is actually growing in the strip of grass that runs between the sidewalk and road, it started on one side, (from the neighbor) and has now taken over the whole strip. The area is perfectly level, no low or high spots. Just very annoying as it now seems to be spreading to my actual lawn at the edges, so im trying to kill it off before it takes over that too!

I see you already bought some. If you like the product, you can get a little bottle of it for around 120 or so. 10 dollars a gallon per pack; one bottle makes 40 gallons or only 3 dollars a gallon. I have had my bottle for about 4 years now and still works very well, doesnt lose strength. I store it out of the sun and keep it in a zip lock bag with antihumidity packs(KNO3).