I am a resident of NY and planted a Kouza Dogwood (white flowers) in May 2005. At that time the flowers were blooming. Since the autumn of 2005 and present, the tree has not sprouted any green leaves or buds. The tree looks dead since there is nothing blooming. Is there anything I can do to save this tree? The garden center where I bought the tree had said a Kouza can take 2-3 years to truly come alive. Is this true of a Kouza?