Name: Susan Virginia (Zone 8a) God is the only thing that matters.
I have two Birch Trees and I planted a small raised bed for baby hostas a couple of years ago and a few fibrous roots came up into the soil but did not hurt anything. These fibrous roots will suck all the water out of the soil so you just make sure there is plenty of water for every thing to be happy. I did a raised bed under the trees as a temporary place to over-winter the hostas which I had dug up from the front of the house where they had fried.
It looked so good in the spring that I left it there, I love the look of this and I do not believe it will harm the trees as long as you leave some spaces in-between the beds so the tree roots can still get some air.
I have the main bed in-between the trees, then I will eventually go around the trees and have smaller raised beds scattered around and large pots. I also would like to add river rocks.
Consider the lilies of the field, how they grow; they toil not, neither do they spin: And yet I say unto you, That even Solomon in all his glory was not arrayed like one of these. Mat.6:28-29
