I think you have fungus problems. Maybe brown patch. I think you're over watering.

You can try applying a fungicide, but long term you're better off planting a cultivar that is more fungus resistant.

I think you should slit seed it with some better grass.
I would aalso fertilize it with a starter fertilizer.
Not sure what zone you are in. May be getting a litle late

If you had standing water for days upon days, then you definitely have a fungus problem. Possibly the biggest problem is a lack of beneficial fungi because they were drowned.

I would apply a light dusting of compost to get the soil microbes back in gear. The amount is 1 cubic yard per 1,000 square feet (800 liters per 100 square meters). Sweep all that down with a push broom to lift the grass our from under the compost.

A week later apply an organic fertilizer like alfalfa pellets (rabbit food) at a rate of 10 pounds per 1,000 square feet (5 kilos per 100 square meters). Three weeks later you can double that amount of fertilizer.

It is getting very late to do this so get going.

Also spray your lawn with 3 ounces of any clear shampoo per 1,000 square feet to get better penetration of the water. Spray and irrigate with an inch. Repeat in 2 weeks.

This time of year in your location you should be watering once a month.

Thanks for the replies guys!!

I guess I will try the composting solution first. Is there any specific way to apply the compost to the lawn? I measured my square footage and I have about 1,024 sq ft so I would apply a full cubic yard.

Also, how do you apply such a little amount of shampoo (3 ounces) to such a large area? 1,024 sq ft?

Once a month for watering!? That's way less than I would have thought but I am also a newbie to this. Is there any guide you can link to for my area that would give me an idea of how much water to apply through out different months?

Compost is applied with a wheelbarrow, shovel, and push broom.

For the shampoo, put 3 ounces into your hose end sprayer, fill the sprayer with water, set the dial for anything, and spray evenly around the entire area until all the contents are gone. That will be 3 ounces per 1,000 square feet.

What we're trying to do with watering is mimic Mother Nature. To tend to your grass, you need to keep an eye on it. Water it when the grass tells you. In the winter that is harder to tell. Once a month is good for the soil regardless of whether your grass is growing or not. As the temps climb, you will be watering more. How much more depends on your soil, climate, grass type, grass height, shade, etc. There is no guide for that. In the heat of summer most people outside of triangle formed by El Paso, Palm Springs, and Las Vegas can water once a week. If you are in the triangle, you might need to go to every 5 days and sometimes every 4 days.

Thanks for all the advice guys! Really appreciate it! I'm a younger guy and none of my friends have lawns yet so I don't have many people to look to for advice.

I was out of town last weekend so I will do the top dressing and shampooing this weekend. Are you suggesting to to the top dressing and then shampoo right after on the same day?

Also, a little update: I took a long screw driver and poked it into the ground in a few spots. Where the grass looks good and green, the screwdriver goes in easily and fairly deep. But everywhere that the grass looks dead, the screwdriver will barely go 1/2 inch into the ground. I doubt this is coincidental. I also took a pick-axe and swung it into the ground in the middle of one of the dead spots. It looks like there is a fair bit of soil but it is just really hard. Any thoughts? Would you still suggest I have a fungus problem or something more to do with soil?

Since no replies yet, I'm going to proceed as planned tomorrow: Detatch, pickup and spread 1 cubic yard of fine compost, fertilize, water w/ 3oz of shampoo

Since no replies yet, I'm going to proceed as planned tomorrow: Detatch, pickup and spread 1 cubic yard of fine compost, fertilize, water w/ 3oz of shampoo

Just a thought, and not really that big of a deal since the compost will be so thin, but I would shampoo before you lay the compost. Your trying to get it to penetrate the current soil, no use in going through the compost.

Thanks Ibanez540r! I will shampoo first... Seems to make sense anyways.

Update:

I lightly dethatched the lawn with a dethatching rake. I then shampooed with 3oz of no tears baby shampoo. I then spread 1 cubic yard of premium ultra fine compost.

I noticed today, however, that some of the yellowness seems to be running in fairly distinct lines in the same direction that I originally fertilized. See pic:
{{gwi:119475}}

I also noticed that the back 16" or so running at the base of the rock retaining wall is really green and I remembered that I accidentally did an extra pass there when I originally fertilized. Could it be that my lawn is just really lacking nitrogen?

Would it be ok to do another application of fertilizer first thing tomorrow morning over the top dressing then give it a good 1" of water?? The last time I fertilized was about a month ago and the lawn hasn't had any other fertilizer this summer.

I also noticed that where the house casts a shadow on a portion of the lawn most of the day, the grass is really green....