Gretchen Bartzen

Executive Director

Gretchen recently retired from her position as Director of Development and Parent Relations at The Seven Hills School. She directed a successful 5 million dollar capital campaign for them in 2003 and increased volunteer involvement, annual giving, and the school’s endowment. Her teaching background and participation in various organizations are skills that she brings to achieve the Board’s goal of raising visibility in the community, as well as increasing financial support.

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Billie Hopper

Special Projects

Billie is a California native who has resided in the Bay Area most of her life. She has a bachelor’s degree in Anthropology from UC Berkeley and a master’s degree in Public School Administration from Ohio University. She has also completed numerous courses in Ornamental Horticulture at Diablo Valley College. After a ten-year career in elementary education, Billie worked in a variety of supervisory and managerial rolls for Bechtel, a large engineering and construction company, for 25 years. She has also been a long-term supporter of the Nature Conservancy and was a docent at their Jepson Prairie Preserve for several years.

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Brian Kemble


Brian Kemble has been at The Ruth Bancroft Garden since 1980. He is highly regarded in the horticultural world and is a prolific writer and lecturer on botanical topics, especially relating to succulent plants. Kemble has a B.A. in Philosophy from Antioch College, and he began concentrating on succulents soon after moving to San Francisco in 1971. Brian's work for The Garden has included hybridizing aloes, agaves, gasterias and some South American cacti. Brian has traveled extensively in Mexico, Madagascar and southern Africa, studying and photographing plants in their native habitats. His gardening column “On the Dry Side” appears in several newspapers in the San Francisco Bay Area, and his photos have been published in numerous books on succulents.

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Martín Viveros


Martín Viveros is the senior gardener, having worked at the Garden since 1990. He moved to Bakersfield, California from Mexico in 1984, where he began to work in vineyards there. His cousin first introduced him to the Bancroft's in the late 1980s and he soon moved to the Walnut Creek area to begin work in Ruth’s garden. He did not know much about cactus and succulents at the time and Martín said at first he did not enjoy working with the especially spikey cacti. He wondered how Mrs. Bancroft could handle them without wearing any gloves. After six months though he began to really enjoy the job, though he does wear gloves when working with cacti. He currently divides his time between Mrs. Bancroft’s private gardens and the Ruth Bancroft Garden. Mart ín also has his own landscaping business, and enjoys cooking for a special event catering business he created called “Tacos Michoacanos” providing signature dishes for weddings and other private gatherings.

Walker Young

Assistant Curator

Walker joined the staff at RBG in January 2012 and since then has come to function as custodian of the Garden’s aesthetic. He acts as point person in the collaborative process of preserving, renovating, and rejuvenating Mrs. Bancroft’s beds, taking particular joy in sculpting undulating mounds and arranging rocks in the Garden to form a unifying backdrop and compositional foil to the Garden’s plant collection. Along with the curator he propagates rare succulents from seed to be used in the Garden and manages care of the private collection. His most significant contribution to the plant palette has been the donation of a cycad collection, which he has used as an intermediate texture connecting the garden’s collection of radially symmetrical rosettes with its softer drought-tolerant herbaceous perennials.

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Alice Kitajima

Volunteer and Program Coordinator

Alice joined the Garden staff in February 2016 from the volunteer ranks of the Garden, where she had been assisting Curator Brian Kemble and Horticulturist Ryan Penn in plant records management and care since 2015. She will help the Garden continue to develop the Adult Education and Volunteer and Intern Programs at the Garden. Alice’s roots in the horticulture world are long and strong! After graduating from UC Berkeley in Forestry and Music, she worked first as an intern at the New England Wildflower Society’s “Garden in the Woods” and then at the Arnold Arboretum as an apprentice in Boston. Next she spent time in Southern California working at Descanso Gardens in La Cañada, followed by several years as a botanic gardener at Lyon Arboretum at the University of Hawai’i. There she helped maintain the plant collections and wrote grants and edited articles for the Arboretum newsletter.

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Anna Halverson

Program Manager

Anna wears many hats here at the Ruth Bancroft Garden. Her primary responsibility is to administer the Garden’s Membership program. In this role she has streamlined membership levels and is busy with the implementation of a brand new membership database. The new system, which will go live in May 2019 will improve our member experience and renewal process. Another key role is to direct the Docent program—training, scheduling and supporting the volunteer tour guides who provide interpretation of the Garden’s collection for our visitors. She also manages the Children’s Education program, developing curriculum for school field trips and Scout programs. Anna has a Master’s in Public Garden Management from Cornell University and has worked at the Lewis Ginter Botanical Garden in Richmond, Va and the New York Botanical Garden. Anna joined the Garden staff after having volunteered for two years with the Children’s Education Program at the Garden, helping to develop and run new summer programs for kids and families.

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Angela Hartman

Marketing Manager

Angela is excited to boost the Garden’s presence in the community and increase plant sales as Marketing Director. She joined the team in fall of 2016, and has experience handling marketing and communications for several local non-profits. She earned a BA in Broadcast & Electronic Communication Arts from San Francisco State University, and worked as a news reporter for a station in Joplin, Missouri. After getting married, she moved back home to the Bay Area where she now resides with her husband, son, daughter, and dog. When she isn’t at work, you can find her getting her hands dirty in her garden, or hiking our local trails. She also enjoys hunting for antiques, cooking, camping, and anything involving the outdoors.

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Tracy Fletcher

Sales Director

Tracy Fletcher grew up in Kansas City and joined Verizon Wireless at a very early age. She worked through the ranks and moved many times with the company. She grew up and started her wireless career in Kansas City. From there she moved to Des Moines, then Atlanta and finally to Walnut Creek, CA. After almost 30 years of service she felt it was time to leave the corporate world behind and pursue her true passions: animals and gardening. Tracy is an avid animal activist and has volunteered for various rescue groups and shelters. When not with four-legged friends she is in the garden. Her business experience and love for plants made her a great fit for The Ruth Bancroft Garden. She loves that each day is a new adventure and allows her to meet so many great people. Her dog Freddie is frequently by her side when working at the garden which allows her to combine her two favorite things.

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Melissa Sunbury

Marketing Director

Melissa moved from Southern California to the Bay Area in 2006, taking a hiatus from her professional career in marketing with DIRECTV, to focus on raising her three children. However, not one to stay idle for long, Melissa immediately began volunteering in her sons’ schools where she has put her marketing and management skills to work chairing various PTA committees and fundraising events. With one son now in college and her two younger children in middle and high school, the time had come to go back to work and she was so happy to find this wonderful opportunity to utilize her marketing skills at the Garden. In her free time, Melissa enjoys vegetable and flower gardening, theatre, and the outdoors. She is currently redefining curb appeal by cultivating an ever-expanding raised bed vegetable garden in her front yard, since her backyard is too shady. Melissa has a BS in Foreign Service from Georgetown University and an MBA in Marketing from UCLA.

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Eric Nightingale

Nursery Manager

Eric grew up in Washington State, where he attended Western Washington University. He and his wife moved to California in 2011 for her to attend the Culinary Institute of America. The plants, birds, and sunshine of the state convinced them to stay. Since then Eric has been an avid gardener and official plant nerd. He has been a nursery manager since 2014 and was thrilled to join the Ruth Bancroft team and be a part of the mission to support this special place.

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Stephen Lysaght

Garden Host and Membership Sales

A native of Sacramento, Stephen moved to the East Bay when he was 12. He attended San Francisco State University earning a BA in Interdisciplinary Social Sciences. While raising a family of 4 daughters Stephen worked for the US Postal Service for 20 years. The last 25 years of his career Stephen served as President of American Postal Workers Union Local, based in Walnut Creek. He first visited the Ruth Bancroft Garden soon after moving to Orinda from San Francisco 21 years ago, and was inspired to become a docent and begin creating a small “dry garden” at home. Following his retirement, and having volunteered as a Garden docent for 13 years, Stephen was hired as a regular Garden Host and Tour Guide in June of 2015. Stephen is an officer of the board for the San Francisco Succulent & Cactus Society, a former librarian for the California Cactus & Succulent Society, and a member of the San Francisco Bromeliad Society and East Bay Bonsai Society. Besides gardening, he also enjoys travel with his husband, and spending time with their 5 daughters and 6 grandchildren.

Eleanor Lonardo

Nursery Associate

Eleanor Lonardo joined the Garden staff as a Nursery Sales Assistant in October 2016. Eleanor comes to the Garden with lots of experience in retail, photography, marketing and little bit of coffee - but, her first love is horticulture! Two years ago she planted a bio-intensive flower/vegetable garden to add to her several years of experience as a collector of dozens of potted houseplants and succulents. She also became the “plant whisperer” for States Coffee in Crockett while she worked there. Recently Eleanor also completed a digital course in cultivating cut flowers through Master Gardener Claire Day. She likes to learn all she can about California natives and cactus gardens like RBG.

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Cricket Riley

Nursery Associate

Cricket joined the Garden in April 2017 after being a member for several years. One of her favorite parts of working in the Nursery is helping customers find the best water wise plants for their gardens. She is a strong proponent of idea that gardens can be lush, beautiful and sustainable if you use climate appropriate plants. Cricket has a BA in History from UC Santa Cruz, a MA in Broadcast Journalism and Near Eastern Studies from NYU and worked for CNN in New York and Los Angeles. She is slated to receive her AA in Landscape Architecture from Merritt College in May 2019.

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Kelly Duckworth

Nursery Associate

Kelly was born and lived in Napa until she was 21 and moved to Hawaii. 15 years ago, she moved back to the mainland after her son Dylan was born. She has experience working in retail and restaurants. She unearthed her passion for plants when she started working for OSH. Kelly is a big fan of all things Halloween and sushi. Her favorite plant in the garden is Tradescantia because of the beautiful purple leaves and tiny purple flowers but loves any succulent that is weird and dark. She's also a big fan of the SF Giants.

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Marck Menke

Nursery Associate

Marck works part-time in our Nursery as a horticulturalist and sales associate. He was born in San Francisco and has lived the majority of his life in the Bay Area, where he has gardened and studied both wild and cultivated plants and other biota for more than thirty years. His formal training includes a horticulture certificate from Diablo Valley College, a B.Sc. in Botany from San Francisco State University and an M.A. in Evolution, Ecology and Population Biology from Washington University in St. Louis. He also has several A.A. degrees focusing on digital art, broadcasting and cinematography. In addition to his work with plants, Marck's interests include reading, writing, music, art, film making, hiking, exercise, food, and travel.

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Banner photo by John Ricca