kitchen garden vs vegetable garden

kitchen garden

noun
  • A garden used for growing fruit, vegetables and/or herbs for use in the kitchen. 

vegetable garden

noun
  • A small garden, attached to a house, where vegetables, herbs and fruit are grown for household use; sometimes includes cold frames and greenhouses. 

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