brushwood vs shrubbery

brushwood

noun
  • Small trees and shrubs. 

  • Branches and twigs fallen from trees and shrubs. 

shrubbery

noun
  • Shrubs collectively. 

  • A planting of shrubs; a wide border to a garden where shrubs are thickly planted; or a similar larger area with a path winding through it. 

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