Moles! The bane of everyone that has a lawn. There are hundreds of products sold every day to deal them and most are, at best, ineffective. Grub control products are sold under the theory that moles eat grubs, which they do, even though research has shown that moles most favoritest food is earthworms, but who would buy something that killed off earthworms? A mole needs about 1/4 acre to supply the food they need so most likely you have one mole to deal with. Research at Michigan State University found that 1 pint of Castor Oil applied over 2,500 square feet would deter a mole for 6 to 8 weeks. The commercial sprays that contain Castor Oil for mole control do not contain 1 pint and state they cover 10,000 square feet, too little over too large an area.
"Weeds", unwanted plants, are a fact of life. No one has, of yet, eliminated them even after spending large sums of money on "controls". Corn Gluten Meal, CGM, can if applied properly help stop "weed" seeds from growing. When to apply it depends, United States and Zone 5 tell us very little about where you are, but the CGM should be applied about 6 weeks before the "weed" seeds are going to germinate. Beyond that don't get overly paranoid about "weeds" in the lawn
Mowing height can also help with "weed" control since longer grass blades can help shade the soil and prevent some seed germination, and the longer grass blades allow the plants more access to sunlight which allows them to manufacture more nutrients which allows the plants to grow thicker stands of grass which competes with the "weeds" and can crowd them out.
Watering is also important. Infrequent and deep is better since often and shallow helps support "weed" growth more then good healthy turf growth. Turf grasses need about an inch of water per week unless the weather is quite hot and/or windy, both of which suck moisture. Along with proper watering is adequate levels of organic matter in the soil which helps hold moisture in the root zone.

Kimmsr-

Thanks for the detailed reply. The info you provided is helpful. I do have some other questions though. I live about an hour southwest of Chicago in zone 5, late last summer I did the jar test and My soil is about 85 % hard clay, which is strange because one block away the soil is about 70 % sand. Last year I did 2 applications of the shampoo and it helped out with water retention.
How do I know when weed seeds will start to germinate? Also what can be done using CGM that will not give me positive results? It sounds like timing is everything with that. My issues with weeds didn't surface until July last year. But they were way outta control. I just figured there would be something I could do early in the year to prevent a lot of them. This lead me to CGM which I'm having a very difficult time finding in my area. In the past I have always mowed at the highest, or second highest height setting on my mower, cutting no more than 1/3 inch at on time.

We have had a ton of precipitation this winter and the ground is very moist. I don't know how much of an impact the temps are but we haven't had consistent temps over 40 since last fall. Late March into early April looks like we will be hitting mid 50's consistently. As for watering I learned that I was doing that all wrong as well, listening to the lawn care company they tell you to water every other day, even the irrigation company suggests the same. I'm glad I found this communityðÂÂÂ

As far as the mole issue I have tried a few different things to combat them. Good to know that i may only have one to deal with. I have had success using both methods but no consistently. The first method I tried was a little metal mole trap that you press into the ground with your foot over their tunnel. After moving this around 4 or 5 times I caught one and that Tom care of my problem for the rest of that year. However I looked toward a less lethal approach. Which lead me to Dr. T's whole control. This is 100 percent castor oil and this also worked for about 5 weeks but after that they came back with a vengeance, and I couldn't repel them at all. After reading your post I learned that I need about twice as much as I used. The bottle says the pint will treat 5000 sq feet. So I guess I will continue to use the trap and the whole control. At least I had some kind of results using both methods.

One last question I have is do I over seed? I have read conflicting posts about this, from "you never need to over seed KBG" to "over seeding will help build thicker KBG turf" either way I have not done this in the past 2 years. The lawn care company would over seed when they aerated the lawn.

That distribution of soil types is quite common and is generally attributed to the glaciers and how they pushed soils around.
Shampoo, or soap of any kind, does not help with moisture retention but does reduce the surface tension of water so it flows more freely which means in your clay it gets down into the clay instead of running off. While that may help short term the long term solution is adequate amounts of organic matter in that soil.
Timing of the CGM is a bit tricky, especially give our current weather, but as a general rule of thumb apply it when the Forsythia blossoms.
Overseeding a lawn is something done if the soil is not a good healthy soil that turf grasses can grow well in. You may need to do that until the soil is fixed but if the soil is a good healthy soil most all grass plants will grow in quite well without needing overseeding.

It is my experience with CGM to apply it when the weather is hot and there is no chance for rain for 2 - 3 days. If the CGM gets wet it will become moldy. It did work, sort of, but timing is definitely is an issue as it is a pre-emergent weed killer. The best way to have a healthy lawn is to focus on the health of the soil. Weeds thrive in unhealthy soil. The weeds purpose is to increase the organic matter and microbial activity in the soil so as long as your soil is not healthy you will always have weeds. Any type of weed and feed or chemical fertilizers destroys the life in the soil and causes the soil to be unbalanced. You will never get rid of weeds that way. Feed your soil with organic matter by topdressing or using compost tea or liquid compost extract. The transition to organics from chemicals takes a couple of years so patience is necessary. Good Luck and thank you for doing it the natural way.

The concept of using CGM was formed out of the Iowa State University. I would encourage you to first read How to use CGM and all of the other documents on the ISU CGM Website.

Timing is indeed critical. It should be put down when the Forsythia blooms or if there are 3 consecutive 50* days (whichever comes first). Also, be sure there is no big rain for 2 or 3 days after the application. The first pass will be effective for 5-6 weeks, so you will want to reapply again probably sometime in late May/Early June. Different weeds pop up at different times, so you need to be vigilant. In the Northeast, the first round blocks the dandelions, while the second round protects against crabgrass.

More important than timing is ensuring that the product you are putting down is the real thing. CGM from a feed store is not the same thing as certified CGM. Usually you will see on the label that it is formulated to Iowa State University specifications and certified. I have used Espoma and Jonathan Green brands in the past. It can be difficult to find locally, I have had the best luck with websites that will do free shipping to their local stores for pickup.

The last aspect is that you are putting down enough. 20lbs p/1000ft is probably the minimum and studies show you can literally go as high as 80lbs without damage...really, with organics, the only way you can do damage is if you smother the lawn.

It is said that it takes 3 years before the CGM is at 80-90% effectiveness. The first year is something like 40%, then 65%, then 80-90%. At that point, you will have build up a shield and as long as you apply each year after, you will remain relatively weed free...although, it's impossible to block them all. Most people choose synthetics, because it takes patients and time to do it right.