Jeff Gillman is a professor of horticulture at University of Minnesota where he conducts research about "organic gardening" and has written numerous articles and a few books. You can read my book review about his latest book, The Truth About Organic Gardening, in Briar Patch's newest newsletter, due out this week.
By the way, he later claims he was a little harsh on the Garlic and Peppermint Spray. " I do think it might work for insects, but for plant diseases?"
Courtesy of Amy Stewart over at GardenRant.