I have an acre of land. 1/2 is kept up Bermuda, the other 1/2 is a free for all of every weed imaginable in these parts. If anything, the bermuda is creeping into the weedy 1/2. Pre emergents and cultural practices are to thank for this.

So what grass do you have, and what weeds are you fighting?

Really only 1 thing you can do and that is use Atrazine if you can still find it. It is the only herbicide that is truly effective on Saint Augustine. Atrazine kills everything but SA. If you use any other type of herbicide on SA it will likely kill the SA.

There are some new herbicides out for SA, but all reports and indications are they are not effective and a waste of time and money.

If you had Bermuda all you would need to do this time of year is spray with Round Up. It will kill anything green but leave dormant Bermuda alone. Don't try it with your SA as it will kill it.

A fall pre emergent likely could have prevented this to begin with.

I'd bet that these are winter annuals. If you let them be, they would definitely succumb to your brutal summer temps with no effort or herbicide on your part.

If we knew the grass and weed type, it would really help.

It could be as simple as spot spraying with round up in totally dormant Bermuda grass, but until we know for sure.....

Any herbicide is going to be limited in colder temps, though.

I know during summer the grass will grow thick and the weeds will be controllable (heat and proper irrigation encouraging deep roots) I just don't want these ugly things on my lawn over winter. We had a few days rain last week and are getting 70F temperatures and the weeds sprouted up fast.
I've included a picture of the dormant grass and next doors weeds, I tried to get a closeup with the wide selection of weeds.

As for the weed pic, I don't know if you should kill it or make a salad! LOL! Just kidding.

I'm sure texasweed will be able to confirm or deny our suspicions by those pics, so hang tight!

If only it were that easy.

Well butter my but and call it a biscuit, it is Zoysia.

Your in luck. Go buy some Round Up and spray anything green in your yard. It will not hurt the Zoysia one little bit as long as it is dormant.

Second comment come next spring learn how to mow Zoysia, 3 inches is way too high for Zoysia. You need to be down to 1 to 2 inches.

Before you use Roundup (or other synthetic weed killer like 2,4-D), you might want to read this disturbing article:

http://www.safelawns.org/blog/index.php/2011/12/dr-huber-lays-it-all-out-roundup-is-killing-us/

Zoysiasod. I've always been one to avoid chemicals as much as possible. I feel a failure for using it now :( I had to resort to commercial lawn fertilizer as natural fertilizer is surprisingly hard to come by around here, at least in the quantities I need for the lawn.

Grasshole (Not too sure about the name :P ) Thank you for the help. It is very much appreciated.

Problem is that advice is dead wrong with respect to Zoysia and Bermuda, and has nothing to do with root depth.

As for cutting height depends on the variety. The fine blade varieties like Diamond. Zoro. Emerald (looks like you have one of the finer textured varieties) should be maintained with a reel mower at 1/2 to 3/4 of an inch. The thicker wider leaf varieties like Meyers should be maintained between 1 to 2 inches.

It is keeping them short that keeps them weed free, not letting them get tall, causing the grass to shade itself out, thin out, and allow weeds to grow tall and go to seed. When kept short the grass will form a very dense mat and choke out all weeds. Any weeds that do pop up cannot survive keeping their heads chopped off, weakening them, and not allowing them to mature and produce seeds.

As for your watering has everything to do with root depth. Your method is tailored to force shallow root growth, not deep leaf growth. You are doing this by watering too frequently and too little water when you do water.

Zoysia and Bermuda should not be watered until they show signs of wilt. Once they show signs of wilt, then they should be watered with 1 to 1-1/2 inches all at once to drive the water deep into the soil to 6 to 10 inches. Watering deep will encourage the roots to go deep to seek the water. The deeper the roots the less you have to water. The dryer it is on top the better because it deprives weed seeds from water and germinating.

What you are doing is shallow watering, and too frequently. Only the top couple of inches will get wet and the roots will stay right there along with all the weed seeds getting all the water they need to germinate and grow.

Here is a couple of pretty good links to reference too:

http://www.clemson.edu/extension/hgic/plants/landscape/lawns/hgic1217.html
http://www.turffiles.ncsu.edu/PDFFiles/000020/Zoysiagrass.pdf
http://alabama-grass.com/View.aspx?Zoysia-Lawn-Grass-Maintenance
http://edis.ifas.ufl.edu/pdffiles/LH/LH01100.pdf

Note they are all saying the same thing I am telling you.

That is pure Green Mafia propaganda. Sounds like something the EPA (Employment Prevention Agency) would publish.

At least she finally quit quoting that Turkey fellow.

But I agree. Scare tactic BS doesn't sit well with me. I don't go to the organic forum and disagree with everyone there.

I'll probably never agree with the use of Roundup, but Texas-Weed's watering info above is spot-on, and exactly what you need. I love reading Texas-Weed's contributions. He's helped thousands here. I can't say the same for GrassHole, though. And he's mistaken about my gender (I'm sure it was a deliberate mistake--GrassHole doesn't play well with others).

Nope. Honest mistake. Thought I read it here somewhere.

I thank you for your advice, I am taking it onboard and will change my mowing practices.
However I will state that, even though it may have simply been pure luck, until this mild winter my regime has worked very well regarding weed control and my lawn has been pretty lush. Last years drought and water conservation mandates had some detrimental effect to all the lawns in our area, but my lawn did pretty well. I'm not disputing your expertise, I'm simply stating my actual success and lack of problems regarding the lawn itself.
Regarding irrigation the lawn gets 1 inch per week and even if we ignore the advice that led me to divide it into two 1/2 inch sessions I have found that because of the clay soil if I water too much in one go I end up with puddles that evaporate before the water has a chance to seep down and I get a lot of run off. My irrigation (8 zones) runs at 4 A.M. to keep evaporation down as much as possible while not having water sit on the grass overnight. I have not seen signs of disease with this timing.
In an ideal world I would have the financial wherewithall to have perfect soil etc. but I actually have managed to keep a pretty good lawn.
I do genuinely appreciate your advice, I will be acting on it. I just feel I'm being lectured for causing issues I do not have. My issue was weeds suddenly sprouting up in an area next to a weed forest during my lawn's dormant period in a mild winter after we had a few days heavy rain.

While I don't claim to have the worlds most perfect lawn or claim to be worthy of disputing your recommendation or wise enough to consider offering advice to anyone else, I haven't had any issues with the lawn outside the dormant period.

I now feel like I'm being offensive by being defensive and appear ungrateful, I am not, in fact I'm exceedingly grateful for everyone's advice and time taken to respond.

I wholeheartedly Thank you all for your help.

Sometimes we see issues on the horizon that you don't see. Improper watering, for example, will lead to weeds. Weeds lead to chemicals or exasperation, so we try to correct issues we see before you see them.