Sodding on, or seeding in clay is no problem. Sodding or seeding on a hillside is not always a problem. If you don't like the clumpy grass then you can consider them weeds.

Is your drainage good? Does rainfall drain away from buildings and away from the property or do you have spots where puddles form (I'm thinking probably not on a hill)?

The bumpy lawn will haunt you until you fix it. Now would be a good time. The easiest and best way to fix is to run a tractor and box blade over it. This is a job for professionals. The end result will be that all the grass and weeds will be removed from your yard, but the drainage will be perfect and surface ready for planting.

Before going any further with this, I think you need to answer that question. The time it takes should be a morning to have someone do that for you. If you want to level the lawn yourself, then search this forum for the terms, "proudx, sanding, leveling," and you should find the thread on leveling. The caveat is that he leveled a bermuda lawn that was well cared for to begin with.

If you can decide how you want to proceed between those two approaches to fixing the unevenness, then we can help you get a yard restarted.

I, too, have a lawn care advice question. We live in Michigan and have noticed over the last 1 1/2 weeks that something is overturning our soil. Since I am a golfer the best analogy I can use is it looks like divots all over the backyard. We are pretty sure it is not a dog. Do you know what it could be, and what can we do to ward off our
"destructor"?

sawinma,
Welcome to the GW lawn forum. There is no official greeter, but welcome anyway!!

The way this works is if you have a question that differs from the original poster (the OP), then the best way to get a lot of replies is to start your own "thread." You can do that at the bottom of the forum page. Be sure to use a subject that relates specifically to your problem. "Need lawn care advice," is pretty weak. Yours might be, "Mysterious divot holes in lawn."

If you can post a picture of your mystery divots that would really help. Search around GW to find the process for posting pictures. In general terms it looks like this (img src="http://yourImageURLHere.jpg";) except the parentheses are replaced by . The quotes in the code are important. The image has to be hosted somewhere like PhotoBucket or your favorite online location.

With your screen name I would guess that your initials are SAW and you live in MA, but to be sure, it really helps us to home in on where you live. Zones are really not that helpful because the zones run across the country through all kinds of soils and critter habitats.

Brian, you have 3...no, four things against you for attaining a good lawn and its a quetion whether you have the will and the way to correct it.

First off, the trees. Trees are notoriously thirsty--they drink what moisture in the ground and leave little for grass above. Since most trees' roots are within 18" of the surface of the soil, you can see that not much moisture can escape them. So we must invent a way to help the ground retain moisture.

Two, clay soil. It can grow many plants successfully---but I don't think a good lawn can be obtained unless we try to change what a clay soil does---retains too much water in the wrong places.

Three, a hillside. Since water retention is going to be a problem the grass stands little chance of keeping what moisture is given by you---or by the Man Upstairs.

Four, Sunlight. Some good, some bad, some very bad.

One at a time: Trees, the grass below has to be one that will stand up to how the tree allows sunlight to come through. There are different grasses for sun and shade.
Sometimes they are a mix....but you can buy for special places.

Clay soil: To help it retain moisture, you must try to get into it some organic matter. Compost, hay, straw, newspaper, old dry grass clippings ..and many other amendments including peat moss.

Compost is the one leading soil amendment which can help your grass grow. Organic material aids the soil into water retention. It will soak up water and help it retain water over the wider area. It will help break up the clay soil.
Getting it into the soil might be a problem. If the ground is not thought to be any good, then rototil the organics into it. Go down at least 6 - 12 inches and incorporate the material as you turn it over. At the same time look to improving its drainage.
You can read for yourself about "compost".

Hillside: Unless you reduce the grade, you will always have loss of moisture through run-off unless you improve the soil ability to hold onto water.

Sunlight: Might the trees be pruned in such a way to allow more sun penetration. Shade is always going to be the problem. Unless you can improve sunlight in shady areas, you will forever have a problem keeping the grass.

Feeding the grass will help it grow and retain its greeness. High nitrogen lawn fertilizer, given in spring and during a schedule through the season is called for.

If you can see yourself purchasing some compost, it can be given to your lawn over the surface twice a year...spring and fall. Fall is the best time to overseed--it has less competition and the cooler weather prompts the grass to grow.

For any area you can figure out how much topsoil or compost you need to cover a particular area.
Multipy the width of the area, times the length of the area in feet...giving you square feet. Multipy that times the depth in inches....and divide that figure by 1000 and multiply by 3.
That gives you exactly the number of cubic yards needed to cover the area.
For that, do not add ontop of the grass any more than 2" at any one time. More will suffocate the grass.

Sod. Sod cannot be grown ontop of grass that is presently there.

Now, if this is all too much to think about, then consider putting down some Dutch White Clover which will take over a lawn and needs no fertilizer--it takes the free nitrogen right out of the air. It stands up dog urine....but...
wait....you have shade. Clover will not grow in shade.
So that's out.

I guess its grass or nothing.

I have often thought about writing a book on organic lawn care but when I sat down to get organized, it turned out to be a pamphlet. Organic lawn care is just too simple to make it into a full book. It might be easier to write a book about how not to do an organic lawn.

I agree with jeannie that clay soil needs "organic matter" but I disagree with what that means and how to get the OM into the soil. If Mother Nature wanted the soil to have newspaper, peat moss, compost, hay, straw, or grass clippings buried in the soil, She would have covered the earth with millions of pigs. Instead She covered the Earth with cattle, antelope, deer, sheep, and goats. When left alone, Nature covers the Earth with animal dung which is then sometimes buried by dung beetles. Compared to the mass of other organic matter in the soil, that is minimal. There are two other kinds of organic matter that matter more. Those are roots and microbes. Grass roots have the characteristic of dieing every year or two and being replaced with new roots. The old dead roots are supposed to be there in the soil. The other organic matter found naturally in the soil is collectively referred to as microbes. These are bacteria, fungi, protozoa, and microarthropods. These critters decompose dung, grass clippings, dead roots, dead insects, and dead animals that fall on the surface of the soil. Each species has it's own habitat. Some live above the surface, some at the surface, and others live at varying depths depending on many factors. The microbes cannot live too far away from their normal habitat, so if they are stirred up, say with a rototiller, the population of every species of microbe will suffer. The population of fungi suffers most because they grow outwards in long strands that get chopped up by the tilling. So anyway, it might sound like I'm drifting but my point is that in my humble opinion, the rototiller has no place in lawn preparation. If you want to maximize the organic matter in your soil, grow grass (because grass sheds its roots), feed it with organic fertilizers (because they feed the microbes and chemical ferts do not), never use chemical fungicides (because they kill fungi), never use chemical insecticides (they kill the microarthropods), and never use chemical herbicides (just don't). Not that anyone has suggested you use the chemicals, I'm just saying that if you want to maximize organic matter, the organic method works and rototilling does not.

Regarding shade: there are some plants that look like grass but grow in deep shade. Monkey grass is one. I have some dwarf monkey grass in my front that never needs any care at all.

Regarding calculations: Another way to calculate how many cubic yards of something you need is to use Google. For example paste the following into Google and hit Enter for the answer

20 yards x 10 meters x 1/4 inch in cubic yards

Google recognizes it as a calculation and does all the unit conversions to put the answer into the final terms you want. Here's one I use a lot

1 gallon per acre in ounces per 1,000 square feet