On Thursday, June 26, 2014 6:20:58 PM UTC-4, Guv Bob wrote:
I'm trying to get revved up for the weekend lawn job....



How's a good way to break up hard soil? Since it's all level, my first thought is to soak it good for a couple of days. I wonder if renting an aerator might also be good.



Most of the soil is fairly easy to dig down 2-3 inches, but about 1/4 of the back yard is bare & hard as a rock. When I was taking soil samples, I had to use a pick to get down that far. Good news is that the pH and nutrients for the entire yard, including this bare area, were the same. But the whole yard is dry and hard deeper than 3-4 inches.

Without knowing what the composition is of what's there,
impossible to say. But if it's as hard as you describe,
a core aerator isn't going to work. It's made to penetrate
reasonable soil, not stuff that you need to use a pick axe on.
Someone said a rototiller will just walk around, so too will
the aerator. If there is non-existent decent topsoil, part of
the solution might be to buy screened topsoil.