Gardening and Landscaping on top of rock (growing plants, grass, trees)

[mongoosedn]

So I recently found out that my house is sitting on a layer of rock (conglomerate of cemented cobbles to be exact) that is about 18" under the soil. This rock can be thin in some places or several feet thick in others.

Since this rock will limit the depth that roots of trees and plants can go, I plan to jack hammer some of it out to get better drainage and more space for roots to grow. Does anyone here have experience with growing plants in these conditions? How successful have you been? I'm probably going to go down another foot or two depending on how much work it turns out to be.

[Butterfly4u]

Mongoose,
Your not going to believe this, but I do have experience dealing with the conditions you have.
In the past, I bought an old historic home with a small back yard. The house was bilt in 1850, Lincoln was President.
I started planting small trees and bushes in the backyard for privacy and started hitting something solid.
Low and behold, there were old bricks, everywhere, the entire back yard had been old bricks and someone had put dirt on top and planted grass.
Now, I am not that young anymore, and I was determined to have some kind of nice plantings in my back yard, not just all grass.
It took me 2 years to finally dig up all those bricks. I had alot of them.
I used some for bed "liners" and they looked nice, but had to throw alot out.
I understand you want to remove those rocks and stones, you have to.
Your plantings will only grow so big, then suffer.
Good Luck. Try to clear only the areas that you really want to plant something in.
Use the rocks you dig up for the garden.
I moved from that home since then, but boy, was that a PITA.
Do in spring or fall when it is cool.
I just used a shovel so I could feel every brick and get underneath of it to pull it up.
Good Luck to you.

[ArkansasSlim]

mongoosedn, you will not believe the force tree/shrub roots can exert. I spend lots of time in the Ouachita Mountains and have seen unbelievable examples. Of course it depends on what you are planting, but in the case of larger trees or shrubs (with deep roots) all you will need to do is jack-hammer a hole through the stuff, plant, and it will take care of itself. If you cannot get all the way through, they will still do their job but will take longer. For shallow rooted plants which normally have their roots near the surface, that will not work, but with a couple feet of soil even they will make it. Of course they will need more water (from you) due to the lack of available moisture. And I would not try to take out the whose mess, just dig/jack-hammer individual holes. Good luck.