Espalier

verb: the technique of training trees through pruning in order to create formal "two-dimensional" or single plane patterns by the branches of the tree. This makes them ideal not only for decorative purposes, but also for gardens in which space is limited.Certain types of trees adapt better to this technique than others, although any fruit tree will theoretically work. The branches of the plant must be long and flexible. Examples of trees that take well to espalier are apples and pears.