earth up vs germinate

earth up

verb
  • To cover the stem or leaves of plants with soil, as to encourage root growth or protect from cold. 

germinate

verb
  • Of a seed, to begin to grow, to sprout roots and leaves. 

  • To cause to grow; to produce. 

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