Can't see your photos.

Where do you live?
How often do you fertilize and with what?
How often do you usually mow?
How high do you usually mow? You should always be mowing bermuda on the lowest setting.
Would you consider your soil to be bumpy?

Don't use a dethatcher on bermuda. It will rip out every piece of it leaving with a redo. Won't kill it, but it will set it back to the beginning.

Find the Bermuda Bible on the Internet and read that. Wait for texasweed to reply. He wrote the Bermuda Bible.

Back to your problem, I think your grass needs to be mowed at the lowest setting all the time. The problem is you are scalping off the entire green blade leaving the brown stem. Bermuda blades only get about an inch long no matter how high you mow. It is the supporting stem that can be several inches long. When you mow more than an inch off, you clip the entire blade. If you mow at the lowest setting, or you get a reel mower and go even lower, then you clip part of the green off and it looks green after mowing.

You might have raised your mower because the soil is bumpy and would look scalped or scarred if you mowed that way all the time. If so that is the basic problem. It can be fixed if you want to do a little work some summer weekend.

Hopefully this link works for the pictures:

http://s1022.photobucket.com/home/Sommy_photo

I live in the DFW area and fertilize with Scotts Turfbuilder. I mow once a week on the lowest setting my mower has (under an inch) I don't think I really have bumpy soil, more just the grass isn't real thick. The brown looks to me to be the old dormant grass, with nothing new attached to it. I will definitely read the Bermuda Bible, thank you for the tip.

Hopefully the pics work this time.

Here is a link that might be useful: A few pictures of my lawn (after a rainfall)

Well first thing is in DFW the winter has been very long and extra cold, so what you are describing is somewhat expected, Bermuda is slow to green up this season..

Next it sounds like you may not being giving the Bermuda the extra care it needs, and some extra steps in the spring. For example, one of the first things you did not do this spring was to scalp the lawn down to remove the dormant Bermuda. By that I mean in March or so just before green up, cut the grass really low, low as you can without the blade of the mower striking dirt. Then remove all the debris.

Good news is it is not too late to scalp it down now, remove the clippings, fertilize properly, and exercise proper mowing height and frequency. At first your lawn will look a little thin, but in a couple of weeks you should see great improvement.

Locate the nearest LESCO dealer, there are many in DFW area. Go down and buy product number 000777 or 39-0-0. Apply 3 pounds of product to every 1000/ft2, and repeat every 30 to 45 days up until October. If you do that, mow twice a week at 1-inch, and keep it watered you will be the envy of the neighborhood.

Do I need to scalp my yard again if i did it in the fall to overseed? What about using weed b gone or something to kill the rye to get the bermuda going in Phoenix?

Ok what applies to TX does not apply to Phoenix. In TX it is not recommended to ever over seed with Rye grass in the Fall like you do in Phoenix.

In TX it is recommended to raise the cutting height in fall to add some insulation value and freeze protection for the winter. You do not have that problem in the Valley of the Sun.

What prod do in Phoenix, Golf Courses, is once the Bermuda starts to wake up and get green is fertilize it heavily, and spray the grass with a secret herbicide to kill the rye grass off. I am hesitant to tell you what that herbicide is, because if applied too heavily it will also kill Bermuda.

So my suggestion is to do one of two things. Let the Phoenix Sun kill the Rye grass off as its days are numbered anyway, or look for a herbicide that is safe to use on Bermuda but poison for Rye grass.

Thanks TW. I will continue with my past plans and that is to cut the water on a hot week to stress/kill the rye and then fertilize to get the Bermuda going.

TW-

SOme of Lesco stores are now Deere stores around DFW after being bought by Deere but still carry Lesco fertilizers. Thougt I'd let you know.

Yeah I know but they still show up as Lesco on the web.

A quick question on mowing height. I see it's recommended to scalp bermuda in the spring. If you're using a regular mower (not reel) then you'd need to put the mower on the lowest setting. I also see it recommended to regularly mow bermuda at the lowest setting.

So if I scalp at the lowest setting then what setting should I use for all subsequent mowings? Should I simply mow all the time at the lowest setting?

So if I scalp at the lowest setting then what setting should I use for all subsequent mowings? Should I simply mow all the time at the lowest setting?

It is confusing but yes and no to answer your question. A rotary mower can only go down to about 1 inch. If the yard is the slightest bit bumpy or out of level you rotary mower will hit dirt which you do not want to do.

So you have two options with a rotary. go as low as you can go in early spring without hitting dirt and cut and remove the debris. From there your choice keep it that height if there are no high areas that get cut too short, or raise it up a bit.

Note: The scalping recommendation is really tailored for transitional area where in fall you raise the cutting height to provide insulation from freezing in the winter. So this practice is not useful in the warm southern areas where freezing temps are no concern.

Another thing to keep in mind is how often you want to mow. If you're mowing at the lowest setting, you will probably have to mow twice a week so as to not cut off more than a 1/3 of the grass blade, which results in a yellow/brown looking lawn. If you raise it up a bit and go from there, then you can adjust up/down once you see how each mowing affects the look of the lawn.

And if you find that the lowest setting scalps parts of the lawn, you should fix the bumps and dips in the soil surface. That is not a trivial project but it is doable. You can have a putting green surface but it takes a full day's work for two people.

Thanks for the input on the mowing height. Unfortunately, my lawn does have a few spots here and there that need to be leveled. Could someone please provide a brief procedure for how to level my lawn?

Try this link:

http://forums2.gardenweb.com/forums/load/lawns/msg0400530527794.html