Apple trees should be grafted in the spring before growth begins, from around April to May. Grafting works best when trees are under five years old, but is still workable at almost any age.
When grafting younger trees, there should be 1 to 2 feet of branch between the trunk and the graft site. After grafting, cover the graft site with a wound dressing to promote a healthy union of the graft and the stock. Grafts are not always guaranteed to work. Be sure to do all necessary care procedures during the graft and aftercare to ensure your graft prospers.