[2][3] Greenwell attended Stanford University where she became a member of Gamma Phi Beta and served as a nurse in World War II.

After the war she worked with Otto Degener of the New York Botanical Garden on a book series titled Flora Hawaiiensis on Hawaiian plants.

[5] She performed archaeology studies of early habitation sites of Hawaii including Ka Lae (South Point), and wrote other books on tropical plants.

[6] Today the garden contains over 200 species of endemic, indigenous, and Polynesian-introduced plants that grew in Kona before Captain James Cook's arrival.

[9] In November 2019, the Friends of Amy B. H. Greenwell Ethnobotanical Garden announced their successful purchase of the land from the Bernice Pauahi Bishop Museum.