Okay Gary, I'm glad you wrote in months in advance to get your plan checked over.

NEVER TILL to prepare for turf. Yes, I realize every single book ever written about preparing soil for turf has you tilling it. I used to work for a "pre-landscaper," the guy who prepared the surface for the landscapers on new construction. Actually his title was "finish grader." Tillers are never used. I never knew why until I spent a few years reading here at GardenWeb. The tool used to prepare the soil and make it drain properly is a box blade on the back of a real tractor (large back wheel and small front wheel). If you hire a real landscaper, or a finish grader, your entire yard can be done in a morning (unless you have a sprinkler, lots of trees, fences, decks, or patios). All the work is done at the surface and no deeper than an inch. Your underlying soil structure is important to conserve and tilling turns it to an uneven powder. When that uneven powder settles, it settles unevenly. After a few years, the result of a tilled preparation is a rolling surface at best and usually more like moguls that need to be refilled with sand or soil to even things out. The finish grader will know if you need more soil (you don't) and will grade the surface so that rain drains away from all buildings and away from the property. You cannot do that by hand. You also cannot rent a tractor and do it yourself unless you've been doing it for 5 or 10 years.

To assume it is compacted is a mistake. It might be very hard and not very absorbent but compaction is more than that. You can improve the absorbency with a soaker hose set on trickle. Try it. It's free. Set the faucet to a trickle at the faucet and leave the soaker hose running 24/7 for up to three weeks. You'll be startled at how soft your soil becomes. The reason is the return of soil fungi that have died out. The boringly slow soaker provides just the right moisture without shutting off the air for them to come back to life. At the end of three weeks (you'll have to do normal watering still) your soil will be like a sponge. It will be very soft when wet, very hard when completely dry, and it will absorb water quickly when it rains or you irrigate. That is what you're looking for. You don't need to till or add any amendments to achieve that. If I only was allowed to add one thing to ANY soil, it would be a surface application of ORDINARY corn meal (from a feed store) or alfalfa pellets at a rate of 20 pounds per 1,000 square feet.

Here's a plan for this summer. At the end of summer you might decide you don't need to renovate.

1. Deep water but no more than once a week in the heat of the summer. If your first few waterings have a lot of runoff, stop watering and let the moisture settle in. Then come back before the day if through to finish. I water for up to 3 hours per zone, once a week, and my zones overlap by 50%. Then let the soil dry out completely. If your grass wilts before a week is up, water again but for longer this time and try to go a full week. The deep watering develops deep roots that really build your soil's health. The long delay between waterings allows the surface of the soil to dry out and prevents weed seeds from sprouting.

2. Reset your mower to mow at the highest setting and don't bag your clippings. Tall grass does not grow faster than short grass. Tall grass is needed to develop the deep roots because short grass cannot produce enough sugar to grow really deep roots. Tall grass also shades the soil so the soil remains cooler during the days and loses less moisture to evaporation. Tall grass will also keep dandelions and many other tap rooted weeds out. Clovers and spreading plants will still grow, so do what you like for that. I like to pull them by hand. If I have to suggest spraying with something, I start with vinegar on a hot day. If you have to use a chemical Weed-B-Gone spray on each weed is much better than broadcasting dry weed killer everywhere.

If you do these first two things, you should really never have serious weed problems. Insects and diseases are different, so keep an eye out for them.

3. Fertilize with your favorite fertilizer on a regular schedule. I like organic fertilizer, but I'm not sure it makes any difference to the weeds. Insects don't seem to be a problem anymore with all the toads, birds, and lizards that have returned to my lawn since I stopped using chemicals.

Gary,

Agree with dchall but I'll add a bit more since Im in Chicago too.

Our soils are heavily clay and can benefit from lots of organic matter like compost. It is difficult to find in Chicago but its not impossible. Lots of garden centers/ nurseries have it in bulk and absent that places like Gesemene on the north side or Pesce's in Des Plaines have high quality bagged compost once the season starts in earnest. Call around and you'll find it.

If you're actually in the city it isn't likely that your lawn is very big at all. Probably less than 3000sq if that so I wouldn't even trouble yourself with the grader dchall mentions. And a lawn thats 40+ years old probably doesn't need to be re-graded anyway unless you get water in your basement when it sprinkles and if it does I'd give Daley a call on that one. So go ahead and plant the seed in another couple of months then start thinking about soil amending as a separate issue.

If you're actually in the city it isn't likely that your lawn is very big at all

Exactly. I'm near Midway on a 30 X 125 lot. This 30 X 40 section is my back yard, so no tractor and box blade is getting through the gangway!

Been here since 1959. Years ago I had a dog pen in the yard. After the dog, I sodded. This area has since sunk.

Due to the root structure of Merion Blue (up to 48" root depths) along the sidewalks, the lawn has raised. This rise causes me to scalp the edge when I mow. It needs to be graded and leveled.

Devon & Clark is not my cup of tea. The other one I believe is on Rand Rd, correct? I'll be in St. John IN. this weekend and was planning on stopping at Alsip Nursery there.

Renting a sod cutting is another thought I had.

dchall: I do appreciate your time and effort and I should have been more clear. Years ago, before there was Chem-Lawn and TruGreen, there was Chicago Lawn Service. My pop owned it and I was his little helper. All practices you speak of were pounded in my head by pop ... except for the toads and lizards! As for the slow soaking, I will give it a go.

But I do not buy the dirt dust idea from tilling. Not here in Chicago at least, in my experience. I till my small gardem with a Mantis every year. As for the mogul thinking, can't buy that one either. A soft loam rolls out very flat after grading with a 42" landscaper rake. After our harsh winters, frost heaves the soil and it must be rolled again. That's just what we must do to maintain a flat, smooth lawn up here that looks like a flat top hair cut after mowing.

Do understand, I do not intend to sound surly or augumentative.

You've got grass with 48" roots?? That's a major accomplishment! I wouldn't touch it. How did the grubs ever get to that??

Most of the best places I know of for bulk compost are north side or north shore but there is a landscapers contractor place on Lake St., west side.
I don't get down by Midway very often though

Yes, Merion Blue is known to grow roots that deep. Merion Blue was the turf of choice, back in the day. Wrigley Field, Comisky Park and Milwaukee County Stadium all had it for its traffic and compaction tolerance. It just needs nitrogen ... 6 to 8 pounds per 1000 sq. ft. per year

But truth be told, the real reason the grounds keepers used Merion was because it could be cut really very short like Bent and still thrive. So, with the ability to cut extremely short, or allow it to grow tall, the grounds keepers could make a fast or slow infield depending on the visiting team. All within one week, with all that nitrogen. Sneaky eh?

Merion Blue has long since been discontinued and is no longer available. I need to renovate, since I can not properly overseed. Bestlawn will be proud, too! hehehe.

I've seen the Lake St place, but they were closed for winter. Yard was basically empty then.

Mostly, at least that I have seen while in Chicago, the leaves (organic matter) that fall from the trees all over the city are collected and hauled away someplace. At one time they were dumped into Lake Michigan, but not today. There are tons, potentially, of organic matter even on most parts of Michigan Avenue. There are tons of organic matter in Millenium Park and many other places, most of which is simply waste material to be gotten rid of by unknowing people.
Whether any lawn needs to be aerated depends on the amount of organic matter in that soil and since yours has "shrunk" in places tht indicates a loss of organic matter. That some places have a raised sod bed indicates the level of organic matter has increased and seperated the soil particles and made a good growing bed. What your soil needs is organic matter, but not peat moss which is a dead material, no nutrients in it, soil bacteria do not eat it except as a last resort before starving to death, or going dormant. Grasses require 2 pounds of Nitrogen per 1,000 square feet per year to grow really well, but if there is heavy traffic on that turf, such as a baseball field would have, more N is needed to get the growth required to maintain a good looking lawn. Spend some time at this link to an article on Natural Lawn Care from Ohio State University (yes I know not a place Illini fans like) to learn more.

Here is a link that might be useful: Natural Lawn Care

Gary, you admit your soil is very compacted so in using a rototiller you are immediately faced with the hardship of getting the tines down sufficient to turn over what may be possible to fix by simply aerating it.

A professional aerator machine, given that it can loosen up your soil without major digging or turning it over sounds to me a logical alternative.
Overseeding afterwards with a combination 40% Kentucky Blue, 40% Ryegrass and 20% Red Fescue could bring your lawn up to something you can respect.

Instead of the overall killer RoundUp, a more general broadleafed weed killer can be then used when the new lawn has had its second mowing.

The adding of a decent compost---composted cattle or sheep manure as purchased from local suppliers should be laid over the lawn area before the overseeding.

Put the roller aside for a year or two. Depressions found anywhere on the lawn when aerating can be filled at that time.

Overfertilization might well be the cause of many of your lawn's ills. Each year's adding of fertilizer in spring/summer for such long term can indeed cause high nitrogenous readings for your lawn and for that reason you might gain by a proper soil test.
Gypsum may be added to alleviate high pH derived from such long term giving of acid type lawn fertilizers.

The gypsum may aid in breaking up the compacted soil and will help in soil water retention.

Use Milorganite and just plant the grass seed and cover with hay/straw, your lawn will look like Ireland in no time.