Oaks are good trees for shade gardens as they don't have a lot of surface roots.

Be prepared for autumn clean-up! It won't be as simple as raking on lawn.

And although they have deep roots, too much digging would likely be undersirable. Also, don't add soil going up the trunk and I suspect the tree won't welcome a lot of soil added to its root zone either...?

KarinL

You shouldn't need to add any soil. Just start planting. And the autumn leaves can stay right where they are. My shade garden is under a huge triple trunked sycamore. I rake leaves INTO the shade garden.