I have a ligustrum topiary tree on my shaded front porch. Because it has been sitting in the same position for the three years that I've had it (I have neglected to rotate it) most of the leaves on one side of the tree have fallen off and left only dead looking branches. I don't have a lot of gardening experience and I'm not sure if this tree can be saved. Any advice on reviving the dead-looking side, or is it as good as gone?