Your situation is a bit complicated. First off avoid the milky spore until you're sure of the extent of the grub problem. It is very expensive and not 100 % reliable. The way to check for grubs is to go to the edge of dying areas and turn over two inch depth to eight inches square of grass. Check for incidence of grubs in mid spring in the soil just under the grass roots. If there are 8 to 10 grubs you have a problem. Less than 5 per square foot no problem. Now is not the time to be checking for mature grubs. You have another couple of problems that I need back up on. You said you applied Scott's grub control. When didyouapply that? Did you apply anything else? Look at your first picture and note the straight lines in the turf. I think I need a close of both grasses in that area. One may be KBG but the other may be another invasive altogether aside from the fescue question. The lines may be be from an abortive fertizing attempt mixed with another weed grass from last year. Look at the lines in the first photo and think back. Then take clear close ups of the two grasses and send back to me. I want to help you resolve this problem.

Hi JIm - thanks for your response.  Sorry for the late reply back from me.  Here's some info for you:

• I have not seen any recent evidence of grubs.  I will keep looks throughout and testing different spots in the grass from time to time.  I put the Scott down in early June.
• I've owned the home one year and the person who had it for about 4-5 years before me did some moving around/regrading of soil and then reseeding about 3-4 years ago.  So, I think there may some mix of seeds, perhaps.
• I've fertilized once this year, that's it. Tried to get even coverage and don't see any spotty or streaking coverage.  Although, what looks to be KBG (I think) in many areas is green but doesn't seem to be growing in length and in some areas still has seeding on top of many blades.
• In some areas there are small patches of light colored green grass that is very soft and seems to grown in round patches.  Not a lot of that but noticeable.  

I've attached three photo that will hopefully help.

Thanks!!

Eric

Jim - here are a few more pics...

Well one thing is certain, you have a blue grass alright but it is the wrong kind.  This one is Poa annua which is an invasive weed of the first order.  All of the "soft" grass with the seed heads will go along until mid to late august and then brown off (die).  The plant does it's best to go to seed as early in the year as possible and then die off leaving you with basically nothing.  You can go on Google to find ways to handle or treat it.  Just call up Poa annua treatments in lawns and the net should give you a solution.  

Thank you for using the Ask an Expert System.

Thanks Jim!  Have looked a little on Google about Poa Anna and looks like preemergent is an option.  

Do some of the other grasses look like tall fescue?  With all these problems is an option to outright kill the large areas of invasive weed grasses and start over?

Thanks, Eric

The thing to remember here is that if you go with the glyphosate solution and reseeding you cannot use a pre-emergent. It will stop the grass from germinating. So, in this instance forget the pre-emergent until after the new lawn is established. Now this has been said try a grass seed mix that will help you quickly start the lawn. Kentucky Blue mixed with an annual lawn seed that will shade the slower BG as it gets its start. As far as fertilizers go, with lake nearby, try a nitrogen rich formula with no phosphorus and little potash = 46-0-10 or some such. The Phosphorus (remember N-P-K)is the damaging thing for lakes and is naturally available in Michigan soils anyway because thousands of years ago the Michigan landmass was under water many thousands of years ago accumulating plenty of shelled creatures over time. Hope this helps you. I was told in a field seminar yesterday that some seed places have a "safe" tall fescue for shady lawns. I would be careful with this option though until proven wrong. Thanks for using the Ask an Expert System.

Jim - thanks for your time and all the great advice!

Eric

You're welcome Eric. Anytime