I need some ideas how to approach a job that requires installing a retaining wall around a tree that is located on a slight slope. The issues I have to work with is the roots from the tree have surfaced. The roots are approximately 3-4" in diameter and stretch out beyond where the homeowner wants the wall located (beyond the trees drip line). In order for me to do the job correctly, I need to dig a trench 6" deep to allow for my drainage aggregate and leveling sand, however I have the roots that will prevent me from digging a trench in those areas. What are your recommendations on how to approach this issue to complete the job. Also, I am beginning to incorporate hardscaping into my business, and I would like to know how much the going rate is per linear feet on retaining walls? The retaining wall would be approximately 3 layers with a cap using a stone size approx 6"x8"x12" with a ledge. Any help will be appreciated, thanks.