I'm not experienced with this sort of thing, but my first thought is to leave it be. I've not heard that persimmons are grafted to specially disease resistant rootstocks or dwarfing rootstocks, so the reason they are grafted is to propagate the variety. If burying the graft results in roots above the graft, you've sacrificed nothing.

Having the graft below ground level won't hurt the graft if it has healed over, which it should be. In my area, it is generally advised to plant the graft beneath the soil line to improve the chances the scion will survive in a very hard winter, and dwarfed trees are discouraged due to lower hardiness.

The roots are likely native persimmon (or maybe lotos if from a CA nursery). There is nothing horribly wrong with a kaki rootstock, its not perfect but it will work. More importantly here, I believe kaki is less vigorous than either virginiana or lotos and so chances are that even if it roots only a minority of the roots will be kaki. And on the plus side, if the kaki part roots you will have a backup root system if the rootstock dies.

So I would agree with beeone: the best thing to do is nothing.

Scott

Great brainstorm.
I was wondering about what exactly happens when a graft is buried. As I understand it, the upper portion of the graft, the trunk, will follow it's natural rooting tendency, and send out a couple roots, while the lower graft, the rootstock, will as well root.

So really I will probably just have to kinds of root systems going right?

The trunk graft won't out compete the root stock?

So the biggest issue is that the graft could become infected if it wasn't given time to heel? Sounds right.

Thanks,
warren

"The trunk graft won't out compete the root stock?"

I don't understand what you're asking with this question.

I have Fuyu persimmon that I got from One Green World, which is in the northern Willamette Valley. I asked them about the rootstock and was told that they were for commercial propagation purposes only. Not for dwarfing, disease resistance, or soil adaptation.
Normally you don't want to bury the graft because roots from the scion will form and be too vigorous or disease prone.
My opinion is to not worry about it.

My understanding was that nurseries out west tend to use lotus to graft persimmon, but some in the east use native rootstock which may or may not offer additional adaptive qualities (cold hardy, etc).

I thought Lucky had posted some observations about cold hardiness, but recall he was talking about grafts feet above ground not inches either way.

Only 3" deep, in the ground for 14 months, and doing OK - I'd leave it alone.
Will you get 'scion-rooting'? perhaps; but in this case, I doubt that it will confer any more overall vigor to the plant.
I'm unaware of any persimmon understock selections having been made for any specific dwarfing/precocity/disease resistance reasons. They're just seedlings, propagated merely for use as a roostock for grafting named varieties. Use of D.kaki, lotus, or virginiana is largely site-dependent, though there are some problems with some varieties on D.kaki understocks.
Right, Kurt; 'high-working' seems to be working well with my persimmons - and was doing OK with some 'tender' mulberry varieties, as well, but last Easter's Big Freeze Disaster took out all of the 6 or 7 tender varieties I had fostered into a vigorous M.albaXrubra, about 7-8 ft above ground - killing it back to ground level.

is there a low side that water can drain off to? is so, make the basin and excavate enough soil so that it can drain off the water that runs into the basin. You could also do this with a pipe drain, but they tend to fill with debris and soil and need to be cleaned out periodically.
Ultimately, I think the long term survivability of the tree would say if digging it and replanting it is the only way to raise it, the dig it. It's winter now, so you should be able to do that during dormancy.

I think I'm going to leave it alone and see if I get any 'scion rooting', and how that effects the tree. I'm banking on the graft being healthy and not festering.

I appreciate all the feedback. Especially Lucky P's posting.
'They're just seedlings, propagated merely for use as a rootstock for grafting named varieties.'
I think I understand this as that nurseries will lay out a large spread of whatever strong understock for your area, AKA 'rooting scion'?, and will then graft 'fruiting scion' and identify.

Is there a book/website/resource where I'd find out more about rootstocks? Especially what is often used in my area.

As tcstoehr says one green world chooses rootstock for "commercial propagation purposes only. Not for dwarfing, disease resistance, or soil adaptation." So I'm not too worried about it now, but you all have made me interested to learn more about rootstock.

Is it possible to propagate persimmons by cuttings?

Thanks,
Warren

Root cuttings are well-documented as a reasonable method of propagating persimmons - and if you've ever seen the sprouts/suckers that pop up all over the place after a persimmon is bulldozed out, you could understand that.
But, unless this was a particularly productive native persimmon that you wanted to clone, all you'd really have is a vegetatively-propagated rootstock plant.

I've seen references indicating that 1-2cm diameter cuttings of 2-yr old wood can be rooted - and I've tried them - with no success - but I didn't invest a lot of effort in them, and did not have access to mist beds or bottom heat.