There is a research report discussed in another thread that shows a small effect on bloom time based on choice of rootstock. The research centered around testing various plum roots roots for prune plums. It seemed that the maximum change in bloom time was less than a week at most with the majority of test plant blooms occurring within a day or two of each other. Here is the link to the previous thread Rootstock vs onset of bud break? - #14 by danchappell
1 Like