In a message dated 4/18/2014 3:00:31 P.M. Eastern Daylight Time,
alandhaigh@gmail.com writes:
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.
Alan,
Don't you mean the graft union should be well above the ground line?
Another reason to keep the graft union above the soil line is if buried
you lose any protection the understock supplies such as nematode resistance.