Mr. Rosenthal is recognized worldwide as a leading authority on cannabis. He is a California horticulturist and author known for his advocacy for the legalization of medical marijuana and expertise in cannabis cultivation. Mr. Rosenthal has been active in promoting and developing policies of civil regulation for medicinal marijuana. He worked with the state and local governments to implement the delivery of pharmaceutical-grade cannabis to patients with a doctor's recommendation to use marijuana following the passage of California's pioneering Proposition 215 in 1996, which authorized medical use of marijuana.
He has authored over a dozen books about marijuana cultivation and social policy that cumulatively have sold more than one million copies. One of his books on marijuana cultivation is the only book of its type to have been reviewed by the New York Times. Mr. Rosenthal helped found High Times magazine in 1972, then served as a columnist for the magazine during the '80s and '90s. Mr. Rosenthal was one of the original American cannabis writers to travel to Holland, bringing European knowledge and sophistication about cannabis to the US through his books and columns. Rosenthal currently teaches horticulture at Oaksterdam University, the leading trade school for the cannabis industry. His classes teach how to use the latest equipment along with lessons for the best growing techniques. Mr. Rosenthal serves as the executive director of Green Aid, The Medical Marijuana Legal Defense and Education Fund.