Answer: This is an interesting question. You may need to remove some or all of the rocks, especially if they are in a very thick layer. If they are in just a thin layer, you could work them into the soil when you prepare it for planting.
If there are a lot of the rocks, will be difficult to dig through the rock layer and it will not provide a good soil environment for the roots of your new plants.
If you add soil on top of the rocks, you may change the drainage around your foundation. It is important to make sure that the soil level is not too high on the foundation and also that it sloped away from the house. Adding a lot of soil over top of the rocks could create an interface problem where the top soil and subsoil drain at different rates while the rocks drain very quickly. This can cause rooting problems.
If there is plastic or landscape fabric beneath the rocks, you will need to remove that before you plant as well. Plastic blocks air and moisture from reaching the soil and is not healthy for plants as a result. The landscape fabric, if underground buried beneath soil, can entangle roots and interfere with the plants become well rooted and established in your planting area.
I hope this helps.
Q&A Library Searching Tips