Root graft from suckers

[Matte91]

Is it possible to make root graft from suckers growing from the nebari?

Thank you!

 

[sorce]

At first I was all..."a sucker goin' sucker", which would make for a "no", since that sucker goin' sucker and they goin just sucker again.....

Which I think is ugly and a pain in the ass headache when you can find a specimen not prone to sucker, saving you mad time.

However, it doesn't seem like those are "suckers, suckers", just looks like a nebari too poorly tended in it's early days, causing necessary high cuts to make unnecessary ... regular old elm growing from anywheres.

So unlike a tree that actually suckers, which sucks, I think you can ease your pain by just restarting a new nebari with an airlayer above that weak barked part, that seems to be associated with them shoots, either by them protecting the trunk from elements, which may have slowed the development there, or possibly because of continued tooling around down there, which knocked off bark sometime before.

I'd cut that first branch flush and use the wound hole to start the ringbarking.

Sorce

 

[RJG2]

To perform a root graft, you need something with its own roots. A sucker is just a branch from a large root or very low.

You would have to treat it as a cutting - remove it, get it to grow its own roots, then graft back on.

 

[Shibui]

Suckers can also be shoots growing from roots. Not clear if these are actually suckers or accidental root cuttings. Chinese elm is really good at growing from roots that have been removed from the tree.
Root pruning severs roots from the tree (that's why we do it!) If the root ball is not combed out well cut roots are not removed and some will sprout shoots and grow through in spring. I've had that happen a few times here and suspect that's what is happening here.
Suckers can be used for root grafts but, as mentioned, you need to graft so the roots are in the desired position. Can't do that with these as they are. Some species root so well that simply grafting a shoot on the roots and covering the base with soil will allow new roots to develop from existing roots and stem of the graft below graft so it is possible but probably hit and miss.
For more guaranteed results you could try:
Layer the trunk as suggested by @sorce
Get separate plants to graft roots where you want them. Looks like this one will need quite a few to fill the nebari and inevitably some will not succeed so allow quite a few years for that project.
Root prune really hard next spring. Cut the few main roots back to stumps and remove all others growing down or other directions. Sounds lethal but Chinese elm are tough and almost certain to survive. The hard chop will trigger more roots from base of trunk and existing roots and force existing roots to ramify.
While you are repotting you can comb out those new trees growing from the roots you chopped last spring and have a whole new batch to work with.

 

[Matte91]

Thanks guys for your help.

I will figure out later wich method I will use to make a better nebari.
If you are curious or interested then here is a picture of the tree. Ulmus minor suberosa.