You can have dirt trucked in to create a yard. But why is the concrete is 6 foot deep? It would not be poured that deep for any normal reason.

The only thing with creating a yard in this manner would be concern over drainage from the ‘new’ yard/

It’s really weird that they poured the concrete up to 6 feet deep. Is the “parking lot” level? That’s the only explanation I can think of.

Yes, you can put a yard or garden over concrete. Grass only needs about 6 inches of soil for a good root base, but you’ll want to lay down more than that in case there’s a lot of settling. My suggestion is to border the area where you want your yard with a stone or brick wall so that the soil doesn’t spill and spread over time. Pre-plan the plants you want for your garden to see how deep their roots usually go, and lay down about 6 inches more soil than that. If this makes for a really elevated space stairs will be necessary, and you can make those out of the same brick or stone used for the wall. If the area is big enough that you may put in a children’s play set in the future, make sure it’s far away from the dropoff. If/when you sell the house, you’ll want to make sure to mention all of these improvements in your disclosure so the new owners don’t try planting things that won’t grow.

If you don’t want the wall, you could just cut deep enough into the concrete to have a yard level with the parking area, but this will be more costly and create a lot of noise.

Drove past a school that my mother landscaped in 1950 the other day. It was a new school, just built. When my father started to plant a cedar tree in its designated spot, he dug down about 18 inches and hit an old sidewalk that had been covered up with dirt. He planted the tree right there anyway. Beautiful tree, still there, very tall. If a cedar tree could puts its roots around that sidewalk, grass should be able to grow in soil on top of concrete, so long as the soil is deep enough and it’s watered normally.

First of all your drainage might not be very good with six feet of concrete. If there are a lot of cracks and you spray water and find that it drains quickly, you could probably build some mounds and plant things that are not deep rooted or acid loving. What about some super containers with great plants in them?
If you put a few inches of soil there, you could probably grow grass.You might just need to stay on top of fertilizing it. People have built gardens on top of rock, so I don’t see why you couldnt. Maybe you could jack hammer out some of it to make deep pockets for a few large trees or shrubs to send down roots. Take your time and get a lot of gardening books. This is a good time of year to do some armchair gardening. Planning it out will increase your success. Good Luck.
Post some before and after pictures!

Congrats on buying an older home, and remodeling it!

You can plant on top, but I would be concerned with drainage issues, because your soil structure would always have concrete under it.

I would find out why the concrete is so deep! Soil that is contaminated tends to get a nice thick pour of concrete atop it. It shouldn’t be too hard to find out from a local planning board, or from your Title if this is the case.