What is your reason for aerating? If you have hard soil, there is a better way to soften it. But what are you shooting for? Also where do you live?

dchall_san_antonio, I'm in the Nashville, TN areas. My lot was a field where they back-filled parts of it to level it and was going to build the neighborhood club house and swimming pool but then decided to build it elsewhere in the neighborhood. So this lot was compacted by large heavy dump trucks before and during the construction of my house. Of course they added top soil but I wanted to aerate to loosen and get new nutrients down deep. What is your way of softening it?

Thanks.
Bobby

Excellent! This is going to sound crazy but you can soften your soil by spraying it with baby shampoo or any clear shampoo. You can pay up to $70 per gallon for professional surfactants used in sports complexes and golf courses, or you can buy any generic, clear (not cloudy with conditioners), shampoo and get the same results. Apply at a rate of 3 ounces minimum per 1,000 square feet. Water that in with 1 inch of water as measured by tuna or cat food cans placed around the yard. In a week water deeply again. A week after that, repeat the shampoo/deep water treatment and you should be good to go for years to come. You can measure the goodness of this by sticking a screwdriver into your soil before and after treatment. You likely can't get it to go more than 1/4 inch deep. After the treatment it should go a couple inches. More treatments should set up deeper softness.

Here's a summary of soil compaction. Compacted soil is soil with all the air spaces driven out of it. This can only be done with fairly wet soil. It often happens around ponds visited by livestock. It rarely happens in construction because construction people never work on rainy days. But it can happen.

Soil can become hard for a different reason. In normal healthy soil there are bazillions of beneficial fungi that live there. Those little guys send out "hyphae" into the soil to gather food and water. They also swell and shrink with moisture. When they swell they push the soil particles apart. When they shrink they leave openings for air and water to penetrate. This is in healthy soil. When soil becomes dried out for prolonged periods (something that always happens in construction zones), then the fungi die off or severely cut back their hyphae. If you have ever let a loaf of bread go moldy in a bag, then you have seen hyphae. Hyphae are the hairly looking strands of fungal material. When you spray the shampoo and follow up with deep watering, you are establishing the perfect environment for the fungal hyphae to refill the soil. In just a few days they will fill up the soil just like they filled up the bread bag.

Now consider what happens when you use a mechanical aerator to try and achieve the same thing. You can look at the ground and see that you only punched holes in 10% of the soil down to 2-3 inches. Fungi work in 100% of the soil down 10 inches or so and fill it with goodness to the microscopic level.

And please don't be that guy who fights this by insisting there is no scientific proof. The scientific proof is there when you know what to look for. There is also plenty of commercial proof available from the people selling the surfactants. There is also plenty of homeowner proof from forum readers here and other lawn forums. This will only cost you a dollar (Alberto Vo5 at Dollar Tree) to try it out. The mechanical aerator will cost you at least $75 and it will ruin your weekend.

I thought I would jump in since I have used this method and am not far from Nashville. My soil used to be rock hard. After using the homemade soil conditioner for one summer season, I could drive a screwdriver 4 to 6 inches into the ground even after it hadn't rained for a couple of weeks (thanks to Dchall and others). I went every other week the first year and then backed off to about once a month through the summer last year.

Just amazing what it does to the soil.

I didn't actually use straight baby shampoo to start (used BL soil conditioner), but since I have the soil so nice now, after year 2, I'm just going to use baby shampoo.