Question
Why is some of my grass yellow? Thanks.

Answer
It must be Yellow and Brown Grass Week in the USA.  This could be caused by Grubs or it could be a Fungus problem.  Either is a potential problem if you have been using chemical lawn treatments, which wipe out their predators.  Elaborate, please.  Check under the edges of the Yellow and see if you can find little C shaped worms.  Describe the characteristics of this Yellowing.  Worse in cold or hot weather?  Getting larger in spots, or is this overall Yellow?  Anything dead?  rsvp