Inarch Grafting by Ian Tolley OAM

How-To-Video: "This is a grafting technique to permanently restore sap flow to a valuable tree that requires assistance, either because it is aged, or because of a developing incompatibility between rootstock and scion. The skills needed are exactly the same as in normal grafting procedures. There is a number of simple ways to bridge the incompatible area. If the original rootstock is very vigorous, it may tend to grow suckers from its base. These suckers can be used to inarch into the main limbs.

Bend the suckers to sit against the main trunk, well up from the restricted union. Mark the rootstock sides. Try for at least 15 cm of connecting length, the longer the better. Using a sharp grafting knife, cut the bark along the marked lines and peel the strip up. Refit the rootstock sucker and mark it to match the new slot position. Remove the strip of bark from the rootstock. Press them tightly together and, if necessary, use thin nails or a thin screw to lock them in place. Bind the union with tape. Use a tree sealing polymer to exclude air from the top and bottom of the new joint. If the pieces are tightly matched by the nails or screws, there is no need to wrap them together, they can just be sealed with the polymer. If there are no signs of suckering from the rootstock, one or two new, strong rootstock seedlings can be planted close to the original rootstock, without disturbing the tree's root system too much. The rootstock seedlings should be given a season to establish a competitive root system. When sap flow commences the following spring, use those seedlings to inarch your tree following the process described on the previous page. It is recommended to implement inarching as soon as the first signs of an incompatibility develop. The earlier the tree can be assisted, the sooner it will respond to the newly increased sap flow, maintaining good cropping..."

Excerpts from Commonsense Citrus - Chapter 7 – Propagation – Inarch Grafting
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