gardening vs thremmatology

gardening

noun
  • The process or action of cultivating the soil, particularly in a garden; the care of a garden; horticulture. 

  • Any process of care, maintenance, or curation, especially digitally. 

  • The act of a batsman prodding at the pitch with his bat, typically in order to flatten any bumps. 

thremmatology

noun
  • The field of breeding or propagating plants and animals. 

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