Espalier (es-pah-lee-yay) is the ancient practice of pruning and training fruit trees into a two dimensional flat structure against a wall, fence, or free-standing frame. It can also be used for other trees, shrubs and vines, and for plants in pots or in the ground. While it is decorative, espalier has important practical purposes.
This ancient Roman practice was used in the 16th Century in Europe to help grow temperate trees in cooler climates and extend the fruiting season. In colder areas, trees are trained in an east–west direction to receive maximum sunlight. Trees trained against a wall benefit from reflected sunlight and the heat retained by the wall.
In warmer climates like Sydney, it is especially useful for growing fruit trees in limited spaces, like small edible gardens! Espalier trees create attractive fences, and cover unattractive walls or air-conditioning units. They have a good air-flow around the leaves and branches, and the branches have extra support when heavily laden with fruit.
In a common form of espalier, the tree has a central stem with paired horizontal branches, known as a ‘multi-tier cordon’. There are a variety of other styles like fan and candelabra, a ‘Belgian fence’ where several fan-shaped espalier trees are grown together and their branches cross to form a lattice, and an informal style with a more natural shape that is simply pruned to maintain a two dimensional form.
Training trees begins when they are young and flexible and it can take about 3 years to establish a form.
The word espalier is French, and it comes from the Italian spalliera, meaning ‘something to rest the shoulder (spalla) against.’ The word is now used for the practice and for the tree itself.