As with everything in ArchiCAD, how you make it depends on what you need to do with it.
I assume that you are not just looking for a 2d hatch/fill pattern.
You have at least two choices for how to generate an image/rendering of that. You can create a bump map texture to help with some of it, or you could model the stones and grass. Some of both it probably the best option. You create a bump map textures for the 3D stones/pavers.
It may depend on how realistic you need the rendering to be.