I have been reading and it say that you should plant the Tree Peony 6 inched deep and when I read it in Kelly Nursery book it states : Tree Peonies should be planted with the graft at the ground surface. The graft is at the top of the fleshy root. My question is when I looked up how to plant a Tree Peony it states that you want the graft to take root so it has it's own roots. What should I do ? I agree with this statement, but what it the right way to plant the Tree Peony?