In Pollan’s latest book, and in the original Harper’s article, he references the book Opium for the Masses by Jim Hogshire. After listening to the book, I went to the google machine and found that the book is readily available on Amazon, and even on Kindle!

Opium for the Masses: Harvesting... https://www.amazon.com/dp/B004URM3DG?ref=ppx_pop_mob_ap_shar...