"Brooklyn1" wrote in message ...
Guv Bob wrote:

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.

An aerator won't do much on hard-pack adobe like soil except break the
aerator... aerators only poke holes, some extract plugs, but they are
meant for reasonably soft soil that may be slightly compacted from
foot traffic.

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. But the whole
yard is dry and hard deeper than 3-4 inches.

That kind of soil won't let you grow much, let alone a lawn. First
where are you located? Geographical location plays a large part in
soil conditions. In many parts of the US southwest the soil is indeed
like cured concrete, breaking it up will will only result in it going
back to hard after the first couple of heavy rains... then the best
tack to take is to haul in lots of good top soil and do your planting
in that... it would cost too much to amend the type of soil you
describe and it won't be long any organic amendment will decompose
like it was never there.

Thanks. So Cal. According to a county site report for a shopping center in the area, it has a base of older alluvial interbedded silty clay and clay, overlain by interlayered sandy gravel and silty clay.