Grafting a fruit tree is not a difficult task, all you need is a firm steady hand,and a good sharp knife. Rootstocks are available for most types of tree. Scion wood can come from any tree of the same type as the rootstock. (usually !)
The general principle is to make a joint between the scion and rootstock that allows sap to flow between the two ,forming a union that will support both for their lifetime.
In practice good carpentry skills work better than green fingers, cleanliness is essential.
The picture below shows the items required, note; the knife has only one bevelled side. I have video footage of the process but it does not show the detail a macro lens can.
The ‘scion’ is a ripe piece of wood taken from last years growth, usually found in the top of the tree. It needs to be firm with little or no pith.
A cut needs to be made cleanly through the scion at a long angle to create an open face 30-40mm long (1.1/4 inch).
In this face make a second cut approximately 1/3 rd down and 6mm into the wood. At all times use a slicing motion, make the knife do the work, if you push it, that is where the damage will occur to your finger! The scion can then be trimmed to length – keeping approx 3 buds.
At all times make sure the cuts are flat and straight as this is the start of the bond between the scion and rootstock,gaps will not callous (or heal ) and the tree will fail.
In the above picture of the scion face you can clearly see the pale or white ring just inside the green ring of the bark, this is the cambium layer which you have to line up with the same in the rootstock.
The cut face to the rootstock is created in exactly the same way – but it is made very slightly larger than that of the scion, you need to be able to see an edge, or line, around the scion, this is to allow the ‘callous’ to form over the wound -reaching the scion, which it joins to, without this edge the callous will grow under the scion and throw it off.
Rootstock showing the ‘tongue’
Now that you have the two ‘halves’ of the new tree it is time to join them together, place the scion-face to face-with the rootstock and lever it up slightly, whilst keeping contact pressure on both, this will open up the tongue on the weaker scion allowing you to push the two together and slide them down into position.
Above you can see the thin line around the scion, this is an essential requirement for the union.
One other factor is to make sure there is a ‘church window’ on the back of the graft-see picture- this will give long term stability to the graft as it heals.
All that is left is to tie the scion to the rootstock, we use degradable rubber strips which fall off after 6 months or so. Other possibilities are polythene strips or self sticking tape. A tight joint is needed to hold the scion in place for 6-8 weeks. Waxing the whole with hot melted paraffin wax is our normal procedure to seal it all in, if you do not have this available then use vaseline on the cut surfaces.
Callous will form quite quickly above 10c-15c. and a union should be formed within 4-6 weeks. Leave the tie / rubber in place until late summer unless it restricts the stem.
Protect the graft with a bamboo cane also to prevent accidental breakage.
This last picture show a graft one year later. the joint can still be clearly seen but has healed well,it will become invisible (mostly) after a few years.
I will add the video to this post later this week but I’m not sure if it will help !
Please – if the above descriptions do not work for you – let me know so I can adjust / re write to clarify.