Pleaching
Pleaching or plashing is a technique of interweaving living and dead branches through a hedge for stock control. Trees are planted in lines, the branches are woven together to strengthen and fill any weak spots until the hedge thickens. Branches in close contact may grow together, due to a natural phenomenon called inosculation, a natural graft. Pleach also means weaving of thin, whippy stems of trees to form a basketry effect.
History
Pleaching or plashing (an early synonym) was common in gardens from late medieval times to the early eighteenth century, to create shaded paths, or to create a living fence out of trees or shrubs. This craft had been developed by European farmers who used it to make their hedge rows more secure. Julius Caesar (circa 60 B.C.) states that the Gallic tribe of Nervii used plashing to create defensive barriers against cavalry.
In hedge laying, this technique can be used to improve or renew a quickset hedge to form a thick, impenetrable barrier suitable for enclosing animals. It keeps the lower parts of a hedge thick and dense, and was traditionally done every few years.
The stems of hedging plants are slashed through to the centre or more, then bent over and interwoven. The plants rapidly regrow, forming a dense barrier along its entire length.