Grafting, scion wood and where a cider tree comes from

Grafting works because the cambium — the thin layer of dividing cells between bark and wood — will knit to another cambium held firmly against it. The grafter’s job is to cut both surfaces cleanly, align the cambial layers, bind them so they cannot move, and keep them from drying out until they have joined.

Two methods dominate. Bench grafting is done in late winter on lifted rootstocks under cover, usually by whip-and-tongue, and the grafted stocks are then lined out in the nursery to grow away in spring. Chip budding is done in late summer in the field, inserting a single dormant bud into the rootstock, which then grows out the following spring. Bench grafting suits winter labour and small batches; chip budding suits large nursery production.

Topworking, or frameworking, is the same operation performed on a mature tree: the head is cut back and grafts of a new cultivar are inserted into the framework branches. In cider orchards this is how a block of an unwanted variety is converted without starting again, and how an old standard tree carrying an unidentified cultivar can be kept in production while its wood is propagated elsewhere.

Scion wood is well-ripened one-year-old shoot growth, cut while fully dormant, from a tree of known identity and good health. It is stored cool and moist until grafting. Weak, unripened or overly vigorous water-shoot growth grafts poorly, and wood from a tree carrying canker or virus carries the problem into every tree made from it.

Health status is not visible. Apple trees carry latent viruses that produce no obvious symptoms but depress vigour and yield, and certified virus-tested material exists precisely because the eye cannot detect them. For a commercial planting that will stand for thirty years, certified material is cheap insurance. For grafting from a veteran orchard tree it may not be available at all, and the grower is making a considered trade between provenance and certified health.

The other constraint is that a cultivar exists only as long as living wood of it exists. There is no seed bank for an apple variety, because seed does not reproduce it. When the last tree of a cultivar dies without having been grafted from, the cultivar is gone. This is the reason perry pear and local apple conservation is done as an active programme of grafting rather than as a matter of leaving old trees alone.

A maiden is a one-year-old grafted tree, a single unbranched stem. A feathered maiden has side shoots along it. A two-year-old tree has had a season of formative pruning and carries the beginnings of a head. Cider growers buying for bush orchards usually take maidens or feathered maidens, because they are cheaper, establish quickly and can be trained to the system wanted; standards and half-standards are usually bought older, since the trunk has to be trained clear before the head is formed.

Lead times are long. A nursery ordering rootstocks, grafting them and growing them on is working two to three years ahead, which means that a decision to plant a particular cultivar has to be made well before the ground is prepared. For unusual cider and perry cultivars, the practical route is often a bespoke order with scion wood supplied by the grower, and that route lengthens the timetable further.

The alternative is to graft on the holding. Small cider producers and orchard groups routinely propagate their own trees, which gives complete control over provenance and costs little beyond rootstocks and time. It also means the grower carries the identification risk personally, which is a good reason to record where every piece of scion wood came from at the moment it is cut, rather than afterwards.