Question
I had a sweetgum tree taken down and want to plant arborvitaes near and around where the sweetgum used to be.  The problem I have is that I want to place an arborvitae directly where the sweetgum was.  How deep and wide is the root system directly below the base of the sweetgum tree?  What methods can I use to destroy the base of the tree OR is it pointless since it will be too big?  The diameter of the sweetgum tree was about 12 inches.

Answer
You will have almost solid wood from the center of the stump out about 12 inches around. Beyond that point you will hit roots but you will be able to cut through these and plant. Usually folks have the stump ground down below the soil surface but this will still leave wood under the ground that you can not plant on easily. I would try moving 18 inches at least to the side of the stump location and then plant the new arborvitae. You should not have any trouble with them planted here. Not really a good way to dig up this large a stump and the roots will spread out about where the branches hung so all them will not be possible to dig up. This is not really necessary since over time the roots will decay and not be a problem.