Hi, I have an McIntosh apple tree and the original graft is at ground level. I want to graft another variety (Granny Smith) to this tree but it will be difficult to graft to the rootstock since it is flush with the ground. Can I graft my new Granny Smith scion to the upper portion of my Macintosh tree and be ok or do I have to graft to the rootstock section? I also have the same question for a cherry tree. Would this be the same grafting to it when grafting a new cherry scion.