pleach vs wall knot

pleach

noun
  • A notch cut into a branch so that it can be bent when pleaching is carried out. 

  • An act or result of interweaving; specifically, (horticulture) a hedge or lattice created by interweaving the branches of shrubs, trees, etc. 

  • A branch of a shrub, tree, etc., used for pleaching; a pleacher. 

verb
  • To unite by interweaving, as (horticulture) branches of shrubs, trees, etc., to create a hedge; to interlock, to plash. 

wall knot

noun
  • A knot made by unlaying the strands of a rope, and making a bight with the first strand, then passing the second over the end of the first, and the third over the end of the second and through the bight of the first. 

How often have the words pleach and wall knot occurred in a corpus of books? (source: Google Ngram Viewer )