January 21, 2015
I would like to expose the roots on two giant Douglas Firs on my property. The trees have ground covering over them now but would like to put small rock down and feature the root system. How much can I expose without causing damage to the tree? The roots already have busted up the cement walkway to the house, so I will remove all of that and put in a small bridge. Thanks for the help. Joe
January 25, 2015
I would not risk exposing too much. Mainly because fir trees tend to have very shallow root systems. While exposing too much root can harm the plant, I think in this situation the bigger risk would be that you could be making the trees unstable. Without a sturdy root system, a good storm could cause the trees to fall. Fir trees are already pretty notorious for causing damage to property without their root systems being tampered with, and you would be pushing your luck to do so.
If you are still dedicated to this idea though, I would recommend that you consult a local arborist who would be able to tell you after examination if it is safe to remove soil and how much you can safely remove. Your local extension office should be able to give you the name of a local arborist. You can find your closest extension office with this tool: