Ed Rosenthal is the world's leading expert on the cultivation of marijuana. In his more than forty years as the "guru of ganja," he has written and edited over a dozen books about marijuana cultivation and social policy that cumulatively have sold over two million copies. His "Ask Ed" marijuana advice column ran in High Times for several decades and still appears internationally. Beyond the garden, Rosenthal views marijuana law as a crucial social issue and has been active in promoting and developing policies of civil regulation. He lives in Oakland, CA.

David Downs is an award-winning journalist covering arts, technology, and criminal justice for publications including WIRED, Rolling Stone, The Onion, and The New York Times. Downs was a fellow at Northwestern University's Academy for Alternative Journalism in 2004, and he earned a degree in English literature from the University of California at Santa Barbara in 2002. He has received and shared numerous professional honors, including a 2010 Knight-Batten Award for Innovations in Journalism. He produces and hosts the podcast The Hash. He lives in San Francisco with his wife and son.