Propagating fruit trees doesn’t need to be hard graft. Here Peter May – Brighton Permaculture Trust’s fruit tree expert – tells us a bit about the history of grafting fruit trees, and the secrets behind how to graft using chip budding and side grafting methods.
A Roman mosaic from the first century AD shows a method of cleft grafting which has not changed much up to the present day; it is likely that the technique of joining a variety or scion to a root system was being practiced by the Chinese and in Mesopotamia from 2000 BC. Grafting occurs naturally in plants and is commonly seen in Beech and Ivy where the stems have become closely pressed together.
Grafting is used to propagate plants which are often difficult to grow from cuttings and is also used to change varieties or grow multiple varieties on established root systems or repair damage to the stems of trees. The technique relies on the close contact between the cut surfaces of the scion and root system which allows the cambial cells to rapidly multiply and unite the two stems together. Grafting also relies on the close relationship or compatibility between the scion and root system. Apple varieties and ornamental Crabapples are grafted onto apple rootstocks, while cultivars of Norway Maple are grafted onto Norway Maple rootstocks. One of the exceptions is that Pear varieties are grafted onto the closely related Quince as there is no dwarf rootstock available as Pear grafted onto Pear results in an enormous tree not suitable for most gardens.
There are many different methods of grafting, but the two principle methods used are chip budding and side grafting.
Chip budding is one of the main grafting methods used to propagate varieties of many ornamental and fruit trees and is used extensively in commercial nursery production but can also be done on a small scale in a garden. Typical species that are chip budded include Apple, Pear, and Plum together with ornamental species such as Cherry, Crabapple, Ash, Maple, Lime and Hawthorn. The technique is carried out during August and involves cutting a “chip” of wood which includes a bud from one year old scion wood and inserting it into a rootstock. After they have been tied tightly together the chip bud and rootstock are left until the following spring when the rootstock is cut back, and the bud grows out to form a young tree by the following autumn.
Side grafting is carried out during March using dormant scion material which has been collected in January and stored in a fridge or in well-drained soil in a cool position in the garden. The diagonal cut made across the scion with a sharp knife is matched with a slightly larger cut into the rootstock before being tied together with tape. Leaves emerge from the successful graft during the early summer and by the end of July the tape can be removed. Wax is often painted onto the scion to prevent water loss from the graft but it is not always necessary.