Pleaching is a technique for training trees and shrubs into forms that don’t come naturally. It goes back to at least medieval times and might therefore be considered somewhat, well, medieval. In other words, old and not particularly interesting. But not so. The benefits of pleached trees are considerable even in modern gardens. Not least because they provide stylish space, height and privacy.
Pleaching is achieved by bending and intertwining the branches and clipping them into a more or less smooth contour. It is used in the formation of palisades, arches, alleys, and outdoor rooms where the main support for the structure is provided by the trunks and branches, not by a fabricated framework.
Centuries ago, yew was a common plant to use for pleaching. Later on, into today, Lime (Tilia), Beech and Hornbeam trees are common. I suspect that one reason why pleaching in recent times have regained popularity is its advantage as a privacy barrier. It works wonders in small gardens planted right up against the garden perimeter. There it might work in combination with a wall, fence or existing hedge to create additional height and shielding. It can also be used to advantage to define and put focus on a particular area. Alleys work well in this context.