Your dead spots look like dead or dormant annual rye grass to me. In Iowa rye grass both annual and perennial grow very nicely in May thru July. But often it goes dormant or dies out in August. I've been over seeding my Iowa lawn each year with about 50% Tall Turf Fescue and 50% Kentucky Blue Grass The TTF is used in the sunny areas and the KBG in the shadier spots under my trees. Crab grass (aka) water grass in Iowa is easy to spot ... it looks like this. To kill it use Trimec or 2-4D on it. Halts will work to help prevent it's spreading but, you can not over seed when halts in on the ground. As it will prevent the good grass from germinating too.

Even if you had a top of the line digital camera, you probably aren't going to get a positive ID from an birds-eye-view photo. Pretty much all the grassy weeds look alike from a distance - especially when mowed. The distinguishing characteristics are in the fine leaf details, root structure and seed heads. Any, the generic answer is going to be pretty much the same.... you have a grassy weed and you probably won't find an herbicide to selective kill it in rye. You can try one of the products labeled "crabgrass killer" - just be sure to check that it is safe on rye - but I wouldn't get your hopes up. In general, most grass weeds are pretty tough to get our of a cool season turf. You will probably end up having to dig them out or roundup the spots at the end of the season and reseed.

There have been a number of good posts on "yard leveling". Best to use sharp sand, the type used by masons for mixing mortar. I don't recommend mixing anything into the sand, particularly not topsoil or compost. If you feel obligated to add something, you could add one shovel of dry peat moss for every 20 of sand. Mow the lawn short, distribute sand over an area as best you can with wheelbarrows or buckets without making large piles. Use a drag or push brooms and the back of garden rakes to evenly distribute the sand off the high spots into the lower spots and bring the grass blades up. Water well when finished. Alternatives include using a vertical slit seeder to help smooth out the lawn or plug aeration over a number of years. Good luck. Edit: I would strongly recommend that you start with a small area with bags of sand to get an idea of how it is done and the amount of material needed before you commit to a load of sand from a garden center or other supplier. Always visit to make sure of what you are getting before you order. This post was edited by yardtractor1 on Thu, May 29, 14 at 14:42

Thanks PJ. And, Jim, first... cameras can be addictive. ha. Second, those pics were taken with a Samsung L200. Its a nice little camera that I take out on my bike with me becuase it is small and at the price, $120 on sale last year, if it gets broken I won't feel too bad. I got a Nikon D90 digitial SLR for christmas and it takes a much wider range of pics. But, I would recommend something other than a Digital SLR for folks who aren't serious hobbyists. There are some great cameras with zoom lens that are more of the point and shoot variety. Nikon, Canon, even my Fujifilm camera I got on sale did a pretty credible job. You can get a lot of camera in the $350 to $700 range.