Ground layering above graft, Apple

[cishepard]

I have these two (free) apple trees to practice some techniques on, namely trunk chopping, repotting a rootbound tree and ground layering.

I understand how to ground layer with a tourniquet, so my questions are:

a) can I put a wire tourniquet right above the graft and onto the cultivar part of the trunk or should I put it lower so that the roots come out of the same rootstock thay are coming out of now?
b) Should I reduce the rootball and/or tease out the current roots first or just leave it rootbound and raise the soil level?
c) Should I trunk chop first or after I get new roots?
d) is there anything I can do this summer to spread the work out or ....?

I guess I’m basically looking for an order and timeline for the three procedures.
Thanks in advance for any advice : )

 

[Shibui]

Some apple varieties are more difficult to root than others so success will not be guaranteed layering apples.
One of these has bad reverse taper below the graft. The only solution for bonsai is to layer above the graft line on that one. The other one is not so bad so you could layer right on the graft line. Rootstock is likely to layer more easily I think.
Leave the trunks intact while layering. Leaves help to produce roots so the more you have above, the quicker the layer should respond. Do any trunk chop when new roots are established.
There's no point in repotting or teasing out roots because you want to get rid of that part. Intact roots will also feed the tree better to make the layer happen quicker and better.
Timeline; feed and water to build strength. make layer. feed and good care while new roots grow. remove new tree, do any trunk chops and pot up. The stumps should produce new shoots after you remove the layers Next spring you can play with the original roots if you want the practice.
Of course as this is just practice you could elect to do the work in any order if you really want. Just don't expect chopped or root pruned trees to produce good layers quickly.

I'm glad to see you are just using these to practice the techniques. Does not look like much potential for bonsai in either of these.

 

[cishepard]

So, with some more research, I think I have a better handle on the answers.
I’ll start the graft now with the ring bark method. I’m in the PacNW, by the ocean - very moderate summer and winter temps. I’ll leave the apples potted as they are and add a mesh enclosure above the surface filled with bonsai soil and sphagnum moss,
In the Spring, I’ll do the trunk chops before buds break.
Later (late Spring, early Summer?), if there are good new roots, I’ll cut off the old rootball and put them into grow boxes.
Am I on the right track?

edit: cross posted with Shibiu - thanks for your comments! I think I am on the right track!