Replacing a million stones with a Mediterranean garden

[palooka]

We live in a Mediterranean climate and purchased a home with a large, flat garden—about 700 m2. The previous owners didn't want to pay for water or care for plants so they covered most of the garden with concrete tiles or small stones. The concrete tiles are awful: they have a deeply cut pattern that makes it impossible for the kids to skate and also pops even the sturdiest footballs . The stones are larger than gravel, ranging from 0.5 to 1.5 cm, and they go down ~14 cm. That's right, I can dig for nearly 15 cm before I hit anything that isn't more rocks. All told there are more than 30 cubic meters of these bloody stones.

We want to create a Mediterranean garden with several raised planters, but I'm debating whether it's necessary to dispose of all these rocks or if I can incorporate them into new soil. We'd also like a few small areas with grass or a soft ground cover, and here also I'm not sure if it's necessary to remove all of the rocks—ie, what is the minimum depth of soil needed above the rocks for grass or something similar?

Removal alone will cost several thousand dollars, and then filling in so much dirt will easily be several more. I'd like to find a solution we can do ourselves with rented equipment that will minimize waste and cost. Thank you in advance!

Image 1: Current situation
Image 2: Grassy area inspiration
Image 3: Tree inspiration (ignore the stones on the ground, no stones! We love these raised tree beds because trees here tend to grow low and wide, so this raises them up and creates more shade)
Image 4: Path inspiration

 

[Oliver Buckle]

Somebody wants it, all you have to do is find them. I have a friend who bought some land with an old quarry in it, there were piles of granite stones left over from quarrying blocks. The local small port was extending their breakwater and she sold them the lot to infill the centre of it, they collected it in trucks and paid her well. You just need to find someone who loves those beautiful, character filled, tiles, and wants to solid up their front driveway with some large size gravel. They are out there, the previous occupants paid good money for it after all.