Q.Adding Rocks Under Old Dogwood Tree
I have an old, established dogwood tree that has lots of character. Nothing grows under it and I have two Adirondack chairs under it. I am considering putting small white rocks under the tree and between the above ground roots. Then, I would like to place the chairs on top of the rocks. It would help with splashing dirt onto the chairs. I don’t want to do ANYTHING to harm the tree. Will the addition of the small rocks block needed water or anything else and harm the tree? If so, I am not going to try it. Any alternate ideas. . . even a groundcover?

Certified GKH Gardening Expert
This should not affect the water absorption of your dogwood. In fact, it may actually help conserve water, provided you are not placing a plastic barrier beneath the rocks. You should also consider keeping the rocks at least a couple inches away from the tree itself. I know you said nothing grows here, but in the event of any grass or weeds, you could choose to place your rocks on landscape fabric, which not only allows for air flow and water to pass through but eliminates weed growth.