Is the plum grafted on dwarfing rootstock or standard rootstock?

Graft referencing the point where the rootstock and scion meet.

If it is on dwarfing rootstock then you plan to limit the height of the plant so plant the graft 2-4 inches above the soil.

If it is on standard rootstock plant the graft 2-4 inches deeper than the ground level.

The tag says 12 - 14ft - that sounds like semi dwarf to me (there is no specific reference as to dwarf/semi/standard).

According to the ontario government website, the standard for plum root stocks in Ontario is Myrobalan B (My tree was grown in southern ontario). This is a semi dwarf from what I can read.

So, Im assuming, that my neighbor is thinking of old grafting, rather then the semi dwarf. I dont want my tree to loose the benefits of the root stock.

The only reason to plant it that deep would be to have it go own root. But planting it deep will slow down the tree and it isn't very good for it. And there isn't any reason to assume the rootstock wouldn't be hardy.

Will toka grow roots?...If it doesn't' I would plant as is, otherwise the tree could be flopping around in the hole with no roots and might rot?

Thanks athenainwi and Konrad (again :D). My neighbor is extremely knowledgeable, but I had to double check him on this one. My first instinct was to plant it at the same level as in the pot, plus some good compost and or mulch.

I read that japanese plums can be suffocated if planted too deep. So yes, I would assume it would rot. His prunign advice is second to none though. Pruned it up in a minute.