Question
I used too much fertilizer the bag was supposed to cover 5000 sq feet and I have about 2000. I used the Scotts summer, and it burned spots in my yard.  I tried using powdered limestone to offset it, and it worked a little.  Is there anything else I can do to help the burned grass?  I have an inground sprinkler set at 4 days a week at 30 minutes.  I have mostly used the mixed fescue grass seed in the past, I live in St. Louis.  

Answer
Good afternoon Mike:
If too much fertilizer is applied , more water will be drawn from Grass roots. As water is drawn from the roots, plant cells begin to dehydrate and collapse, and the grass roots burn due to dehydration to a point from which they cannot recover. If soil moisture is limited, the damage will be severe.
Slow-release nitrogen sources do not have to be applied as often as do the quick-release sources and that the potential of damaging your grass from over fertilization is greatly reduced.
You need to set your sprinkler so that  you will saturate your lawn with at least an inch of water per week. It is not how many times a week you water but how much water is applied at one time. I doubt that you will water one inch in a half hour. A good way to check the amount of water applied is to set out a series of straight sided containers under your sprinkler system (Tuna cans, Cake pans etc.). Time how long it takes until the one inch level is achieved. You can then use this time figure for future watering without using the cans.
Watering should be done deeply and infrequently to promote deeper rooting.

I would suggest that as soon as possible you try to dilute the fertilizer by watering your lawn with at least one to two inches of water at one time.
Hopefully this will save some of the grass. Fescue, however, will not recover as well as Kentucky blue grass.
The next time you apply a fertilizer make sure it is a slow release type. The only time you should use a quick release fertilizer is in the fall. In fact a late fall application of fertilizer is the most important of the season. Apply when the lawn has stopped growing but is still green. It will increase fall and spring root growth, promote a thicker lawn, and result in an early spring green up.

I hope I have helped. Have a good lawn!
Floyd McMahon