The word espalier is French, coming from the Italian spalliera, meaning "something to rest the shoulder (spalla) against." During the 17th century, the word initially referred only to the actual trellis or frame on which such a plant was trained to grow, but over time it has come to be used to describe both the practice and the plants themselves.
It is a very old technique probably first used by the ancient Romans. In the Middle Ages the Europeans refined it into an art. The practice was popularly used in Europe to produce fruit inside the walls of a typical castle courtyard without interfering with the open space and to decorate solid walls by planting flattened trees near them. Vineyards have used the technique in the training of grapes for hundreds or perhaps even thousands of years.
Wikipedia (accessed 11/6/24)
An espalier does not have to be tightly formal
Espalier practice is about controlling woody plant growth for the production of fruit, by pruning and tying branches to a frame, frequently shaped in formal patterns. The key point is the training of plants to grow in a plane rather than a 3 dimensional shape.
Which fruit trees work best?
Spur bearing apples and most European pears are easily the best subjects for formal espalier training. Plums and cherries can often work but are less amenable to strictly formal shapes while other stone fruit, apricots, peaches, nectarines are in our experience better grown in a vase shape style.
List of apples that may suit espalier training.
Citrus espaliers are generally quite informal with a bunch of suitably growing branches tied to a frame while branches growing away from the frame are regular either tied down if practical or removed. Other fruit trees can be treated the same way.
Ornamental espaliers
Many ornamental plants can be espaliered in a formal arrangement most often with a single vertical main stem and horizontal branches. Camellias, crabapples, hornbeam, ornamental pears and Tilia spp are just some that can be tried.
Just about any woody plant can be informally trained through regular pruning and tying to grow in a 2 dimensional plane.
Establishing espalier trees
In our experience it is best to begin formal espalier training with a healthy tree pruned at planting time to the height of the lowest required branching point.
The pruning helps balance the inevitable loss of roots that occurs when trees are lifted. This helps ensure vigorous bud break in the first spring. The required scaffold branches can then be chosen as the new growth emerges and elongates.
In reasonable growing conditions at least two scaffold levels, for horizontal formations, can be formed in the first season. Primary scaffold fans may well be fully formed in the first season.
It is also important to note that any strict pruning regime that trains branches horizontally or obliquely such as espaliering is itself a dwarfing technique. Medium to vigorous trees rather than dwarf options may be better subjects for espalier training, i.e. trees that left to their own would grow to at least 3-4 metres.
Espalier training apples and pears
Apples from the medium size option, on MM106 rootstocks, and semi-dwarf pears will be suitable for espalier training. You can also choose tall apples, on MM111 rootstock, and full size pears.
The taller options will fill your trellis a year or two more quickly but will require a little heavier maintenance pruning into the future. Espalier trained dwarf trees will generally take longer to fill out a given trellis area.