Jeff Lowenfels

Jeff Lowenfels (Lord of the Roots), is one of the most humorous and entertaining lecturers and writers on the organic gardening circuit. He is a reformed lawyer who went back to his childhood roots to become a leader in the organic gardening movement. He is the author of a series of award-winning and bestselling books, three of which have become bibles for organic growers worldwide, including Teaming with Microbes, Teaming with Nutrients, \Teaming with Fungi., and Teaming with Bacteria Lowenfels has also penned the longest running garden column in North America and was inducted into the Garden Writers of America hall of fame after serving as President. He is the founder of “Plant A Row for The Hungry,” a program which has resulted in millions of pounds of garden produce being donated to feed the hungry every year. He lives in Anchorage Alaska, where cannabis has been legal since 1975.

Annette Huddle

Annette Huddle is Director of Education at the Gardens of Golden Gate Park, comprised of San Francisco Botanical Garden, the Conservatory of Flowers and the Japanese Tea Garden. She has spent the last 25 years responsible for youth, family, and teacher programs at San Francisco Botanical Garden.

Photo credit: Katja Bresch


Paul Spriggs

Paul Spriggs has been rock gardening for 23 years and building crevice gardens for the last 16. He is a professional gardener and landscaper, and an avid plant explorer, photographer and mountaineer. He has a passion for all wild plants, especially miniatures, collecting and cultivating them in various gardens in his hometown of Victoria, British Columbia. Paul learned the art of crevice garden from one of its innovators, Zdeneˇk Zvolánek. He has built many crevice gardens in public parks and private homes ranging from small feature troughs to large installations with many tons of stone. Paul is passionate about spreading the crevice gospel through lectures and workshops, by having served as president of the Vancouver Island Rock and Alpine Garden Society, and by proselytizing to whomever will listen. Paul can be caught growing sunflowers and dahlias as a guilty pleasure and hanging out with his growing family.

Alex Simmons, PlantRight Program Manager

Alex Simmons is based in Sacramento, CA. She has been the PlantRight program manager since October 2019, when she oversaw the transition of PlantRight from Sustainable Conservation to Plant California Alliance. In 2021, she re-launched the PlantRight spring retail nursery survey, and shortly after was promoted to Associate Director of Plant California Alliance. In addition to the Plant California Alliance, Alex is also the Executive Administrator for International Plant Propagators Society–Western Region. She holds a Bachelor’s degree in Sustainable Agriculture and Food Systems from the University of California, Davis. Her background in both sustainable agriculture and landscaping gives Alex a well-rounded view of horticulture and a deep understanding of how plants shape our world.

John Greenlee

John Greenlee is an internationally known landscape designer, horticulturist, author, and nurseryman specializing in the cultivation and study of grasses and grass-like plants. An expert on grass ecologies worldwide, he has been a passionate, potent champion of sustainable design and planting schemes for more than 30 years. His unyielding advocacy for saving the planet, for restoring a balance in and with nature is well said in his meadows mantra.

Katherine Renz

Katherine Renz is an MFA/MA student at San Francisco State focusing on personal essay, natural history, and humor. When she isn’t cycling through the city and trying to talk with plants, she is out exploring California’s wilder lands. Under the pen name Lady Lonicera, she crafts and publishes zines for sale at local bookstores including City Lights and the bilingual Medicine for Nightmares in the Mission District.

Erica Browne Grivas

Erica Browne Grivas is a lifelong gardener and journalist who has been schooled by plants on both coasts. Her feature articles appear in publications including the Seattle Times and Horticulture magazine, and a garden column for Pacific Publishing in Washington. Her writing has earned gold and silver medals of achievement from Garden Communicators International.

Adam Graves

Adam Graves is the Director of Horticulture at the San Diego Zoo. He oversees the plant conservation work, landscape management and agricultural teams of the organization. He is a lifelong ‘plant nerd’ and enjoys learning about all plant groups, but has a special fondness for bamboos and carnivorous plants.

Steven Haddock

Steven Haddock is a Senior Scientist / Marine Biologist at the Monterey Bay Aquarium Research Institute (MBARI).

Steve is working on deep-sea gelatinous zooplankton. He is doing research on bioluminescence, biodiversity, and ecology of deep-sea and open-ocean ctenophores, siphonophores, radiolarians, and medusae. In addition to assembling phylogenies for these groups, he is interested in cloning novel photoproteins and fluorescent proteins from these jellies. See publications for more details.

Steve’s educational background includes a B.S. from Harvey Mudd College and a Ph.D. from the University of California, Santa Barbara. He also holds an adjunct professorship in the Ecology and Evolutionary Biology department at the University of California, Santa Cruz.