North American Fruit Explorers mailing list at ibiblio

[Alan Haigh <alandhaigh@gmail.com>]

If a fruit tree isn't on dwarfing rootstock, as is usually the case with
peaches, the general recommendation I've seen over the years is to plant AT
the graft union and not over it.  I suppose there may be sites where a
newly tree might snap at the graft union if it isn't buried but I've never
seen it happen that way and the last thing peach roots need is to buried to
where the roots are at all starved for oxygen.

A tree on dwarfing rootstock must, of course, be planted well above the
graft union if you want to be assured the tree doesn't root out from the
scion and defeat the size reduction of the rootstock.