cultivate vs naturalize

cultivate

verb
  • To grow plants, notably crops. 

  • To turn or stir soil in preparation for planting. 

  • To nurture; to foster; to tend. 

naturalize

verb
  • To acclimatize an animal or plant. 

  • To make (a word) a natural part of the language, using the native homologue of each phoneme (and often for each morpheme) of the imported word (e.g., native inflections). 

  • To study nature. 

  • To limit explanations of a phenomenon to naturalistic ones and exclude supernatural ones. 

  • To grant citizenship to someone not born a citizen. 

  • To make natural 

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