Those areas of lighter green are almost certainly infestations of poa trivialis. Poa triv is an invasive grass that spreads via stolons. It prefers cooler weather, and goes semi dormant in the summer only to reappear in fall and spring. When conditions are favorable it grows faster than most turfgrasses, and sticks up above the rest of the lawn. It is very difficult to get rid of, and usually the only course of eradication is Round-up, but I have read even then it might come back. Now if this spring those light green areas have a lot of white seed heads, then you have poa annua. I doubt this is the case but there are hundreds of varieties of poa annua so I wouldn't rule it out completely. As far as lawn care companies, most of them, especially the big ones, hire people that have little to no lawn care knowledge. They are trained to come to your house and apply whatever they are told to do and give you the bill. You would have better results doing your own lawn care, or finding a smaller independent that knows what they are doing.

Tiemco wrote:
> As far as lawn care companies, most of them, especially
> the big ones, hire people that have little to no
> lawn care knowledge.

Oh, that explains why my neighbor has had trouble with his company. You call them "lawn care" companies. I call them
"lawn mowing" companies. LOL

I used to work with a guy who was a sales person for Trugreen. He was a salesman, not a grass guy. He learned everything he knew about lawns form the corporate sales pitch they trained him with. Some people they hire are more informed than others.

tiemco's comment "You would have better results doing your own lawn care, or finding a smaller independent that knows what they are doing." Excellent advice. I "fired" two major lawn services in the past 2 1/2 years. I believe that both were using good products -- probably too many visits to do the job -- but think that they were diluting the liquid products and reducing the amount of dry materials. Too many visits? Every other month is not necessary for fertilizing, bug and pests, and fungus control. But 6 a year is what all of the local companies advertise, so they all get on the band wagon.