How small can you graft – Bark or Rind Graft
Another way of grafting smaller diameter scions to larger rootstocks, is by using a bark or rind graft. This can only be used later in the winter or early soring when the bark is lifting or the sap is starting to flow.

Cut into the bark vertically then tease the sides of the bark up, to expose the cambium.

Slide in a prepared scion.

The variety being grafted here is a cherry, and there is always some loose bark. After sliding in the scion and ensuring the 2 flaps of lifted bark on the rootstock are correctly position over the scion, parafilm can be applied to seal the joint.