Answer: Unfortunately, it is very difficult to diagnose lawn problems long distance. This could be caused by a variety of factors in cluding pest or disease issues, uneven watering patterns, or even underground problems such as tree roots, shallow soil due to underlying rock, or inconsistent fill dirt under the lawn. I would suggest you work with our local Cornell cooperative extension to try to determine the cause of the discolored areas and work from there. In the meantime, you may find their troubleshooting/lawn calendar information helpful. Some additional steps to general lawn health to consider might also include a higher mowing height, regular top dressing with compost, and core aeration. You may need to cut and paste the complete url into your browser to make it work correctly.
I hope this helps.
Q&A Library Searching Tips