I know this probably a stupid question but can the scion be thicker than the rootstock in grafting. I have 10 or so plum seedlings that are smaller than the scions I have. I was thinking maybe if I grafted them and then covered the union with dirt it would work. If not I'll just graft on to the larger trees I have and then let the seedlings grow out more. edit: I've read you can use vaseline if you don't have grafting wax. Will this work?