Grafting scions to roots?

Hello,

I’m wondering if anyone has heard of or done this: digging up a tree root (not a rootstock) and grafting it directly with a scion. It would certainly help for propagating trees more quickly or growing them on their own roots. Or is there some sacred connection between stem and root that just isn’t there?…

Say you dig up a root from an apple tree, find a similarly sized scion from the same tree, and graft them together. Is this possible?

Thank you.

It's absolutely possible, but there are a few things to consider, and I haven't personally done it with apples, I've only done it with mulberries and avocados.

The most important thing would be to make absolutely sure that the root you are digging up comes from the tree you think it does. Roots crisscross quite extensively and can travel further than you might expect, so the roots around your apple tree might be from the oak across the yard. What I've done with mulberry and avocado was to dig up (or unpot) an entire small tree, wash the soil off gently, and then carefully root prune segments of the size I want for grafting.

The other thing to keep in mind is you want to minimize damage to the fine/feeder roots, because you want enough root biomass that it will encourage strong growth in the scion. You don't want the plant to be trying to regrow the feeder roots before it starts drawing enough water and nutrients to push growth on your graft.

Possible? yes.
High success rate? probably not.

Woth trying?  Definitely.  Because fun!

So... trying to remember the different names for the layers if a tree.  On a trunk or branch we have the bark, then the phylum, the cambium layer (the part we want touching for grafting to take hold), and then inside that is sapwood.  

If I remember right, the biggest difference between branch and root is that these layers are in a different order.  It would be harder to get the cambium layer to match up - but not impossible.  I would probably go with a grafting technique that lays the two side by each or some sort of drill grafting instead of end-on grafting to maximize the chances of it taking.  

It would be really good to experiment with willow as this would give results faster than on a fruit tree.

The other thing to look out for are things that cause rot as there's a lot of that in the soil and if that gets in the wound/graft, it will decrease the life of the tree.