Is there a way to graft a plum and cherry tree together on one plant?
They are of the same genus (Prunus) but different species... therefore any graft at best will be dificult but nit impossible. That said If it could be done easly I am sure it would have already been done. I know of no success.
Still there is a chance I wousl suggest you go ahead & give it a shot. ..... Let us know the results of your experiment we will be awaithing your reselts.