is it native rock.. or cement ... i dont understand what you mean ...

and what are you planting.. 8 inches is enough for many plants ....

more specificity please ...

ken

sorry.
Definitely not native rock. It was the sub-base for the cement (although I have pulled some huge chucks of cement out as well)
We are planting a variety of different plants in different areas, cotoneasters, boxwoods, some golden junipers. and basically the rock makes up what would be the bottom of where the plants would sit.

so would you then say you have very good draingage....

is it good topsoil .. or clay???

i am thinking 8 inches is just about good enough for anything...

how big are the plants you are contemplating....

care to give us a pic?

ken

Yes, I would say we have good drainage.

We had a ton of topsoil trucked in, so there is about 3 -4 insches of top soil, then another few inches of a denser clay, then several inches of rock, then more of the dense clay dirt.
I can take pictures of everything tonight and post them.
I just want to make sure I am not planting something in soil that wont support it.

The cement is an issue. Especially when relatively new, cement is highly alkaline and can raise soil pH to a level that is unsuitable for many plants. Even though the cement and rocks are now 8" down, they will migrate toward the surface from the action of the freeze thaw cycle unless you live in a frost free area. The best first step would be a pH test. If the area is not too large, digging out the cement may be the best way to go. Contractors are notorious for disposing of excess cement in this way without thinking or caring about the effect it has on the soil.