Grafting is a marriage of the scientific and artistic, and as such may require years of practice to truly master. But anyone can start grafting with only a knife, some scion wood and rootstock, and a little knowledge.
Apple varieties can be characterized as genetically diploid, triploid, quadraploid, etc.; the majority are diploid. This means that, for a diploid tree, at least one pollination partner of a different variety, flowering during the same period, is needed to achieve cross pollination and fruit set. Triploids require two other varieties, and so on. Because of this cross pollination, the seeds contained within each apple are a unique mix of the genetics of each parent. If planted, these seeds would grow into trees producing unique varieties, sometimes similar to one of the parents, but most often not- and often not very edible or otherwise useful!
This is the reason for grafting- by attaching a bud from the desired variety to a rootstock, we can grow the desired variety with certainty. The rootstock will decide the size of the tree, and convey other disease-resistance, precocity, and hardiness characteristics as well, while the bud, or scion, controls the variety.
Vintage VA Apples offers a grafting class each spring, at which participants practice bench grafting, and take home their newly grafted trees. There are quite a few other forms of grafting as well, including bark grafting, and summer bud grafting. Seed Savers' Exchange has put together a wonderful video on bench grafting; and you can find info on other forms of grafting here.
If you're ready to start grafting on your own, VVA now offers a selection of scionwood from our collection, along with a number of rootstock choices. Please visit our online catalog to place your scionwood and/or rootstock order.