spalier is an ancient form of tree pruning that not only allows many larger trees to be grown in a small space - but can actually improve the yield of a fruiting or flowering variety.

In basic terms, trees are trained to a flat plane which can be used to insulate a wall, cover a fence or form a hedge or screen to create a private place. This sort of pruning then focuses the plant's development on flower and fruit production rather than bulk.

So while espaliered trees reward their owners with a beauty that is hard to forget, on a practical side it is much easier to net and harvest fruit from a tree that has been trained this way.