(pleech, playch) 
verb tr.
To interlace branches or vines to make a hedge, decorative shape, arbor, etc.
Etymology
From Old French plechier, from Latin plectere (to plait). Ultimately from the Indo-European root plek- (to plait) that is also the source of plait, pleat, pliant, ply, apply, deploy, display, exploit, replicate, and perplex
Pleached trees: Arbor:

Bicycle: wordsmith.org/words/images/pleach2.jpg [Image source: Dan Ladd www.danladd.com
Usage
"Twenty years ago I planted a row of limes along the drive at the Mills, thinking only to pleach them so they could filter the wind." — Germaine Greer; Lime Trees; The Daily Telegraph (London, UK); Jul 5, 2003.
"Limes are ideal for pleaching because they grow fast, respond enthusiastically to pruning, and have very long whippy new stems that are easy to bend and tie into position." — Monty Don; Pleacher's Pet; The Observer (London, UK); Nov 3, 2002.