Gretchen Bartzen

Executive Director

Gretchen joined the Garden board in 2006 and became the volunteer co-executive director of the Garden with fellow board member and long-time Garden volunteer, Billie Hopper, in 2012. Prior to her service at the Garden, Gretchen served as Director of Development and Parent Relations at The Seven Hills School from 1995 to 2012. At Seven Hills she directed two successful $5 million dollar capital campaigns for building projects, from 2000-2002, and then from 2008-2011. Through her 17 year tenure at Seven Hills she also steadily increased volunteer involvement, annual giving, and the school’s endowment. Gretchen also brings 19 years of experience as a secondary public and private school level educator to her current role as Executive Director of the Garden.

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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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Tracy Fletcher

Chief Operating Officer

Tracy Fletcher grew up in Kansas City and joined Verizon Wireless at a very early age. She worked through the ranks moving from state to state with the company including Iowa, Georgia and finally ending up in California. 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. Her business experience and love for gardening makes her a great fit for The Ruth Bancroft Garden. She started out as Office Manager, then Event Manager, Sales Director and now COO. She loves that each day is a new adventure and allows her to meet so many great people. One of her dogs is frequently by her side when working at the garden which allows her to combine her two favorite things.

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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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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 sons in high school, it was 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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Lucy Kim

Event Manager

A graduate of University of Illinois-Urbana-Champaign’s Advertising program, Lucy has broad experience in event planning, sales, corporate contributions and community affairs programs including organizing numerous black-tie dinner dances and large outdoor cultural festivals, as well as providing event planning, event management and diplomatic protocol expertise for corporate clients and major donors in support of high-level national and international delegations to the Bay Area. As a writer, Lucy landed a 7-page cover story assignment of a highly-regarded international economic journal and had bylines of her articles in several poker publications. When off-duty from The Garden, Lucy keeps busy by planning events for the Northern California Chapter of the NFL Players Association and organizing monthly 100+ player golf outings at private golf courses throughout Northern California. Fine arts being her passion, Lucy loves visiting museums and art galleries and has worked as a volunteer for the Oakland Symphony for many years.

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Kimberly Edgerton Moore

Office Manager

Raised in the Bay Area, Kim has been involved with non-profit organizations and fundraising since she was 17 years old. She was taught the value of volunteering at a young age as a means to give back to the community. Kim has an extensive background in the non-profit world having volunteered or been on the board of many local organizations. Kim attended Pine Manor College in Chestnut Hill, MA and received her BA in Business Management. After living in Boston for 8 years, she moved to San Francisco and began a career in office furniture sales. Working with many large corporate clients throughout the Bay Area, she managed everything from installations of a single person office to entire floors of cubicles and offices, receiving numerous sales awards along the way. Kim continues with her board work with the local middle school parent faculty association and the Walnut Creek Library Foundation. She enjoys spending time with her family, entertaining with friends, gardening, hiking, reading, puzzling, and traveling.

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Kirsten "Freddie" Fleming

Nursery Lead

Freddie Fleming is an East Bay Area Native. After living on Bainbridge Island in Washington State and a cabin in the Santa Cruz Mountains, she is back to her roots in Walnut Creek. Freddie studied horticulture at Cabrillo College in Aptos, Ca from 2015-2017. During that time, she created beds for seasonal fruits and vegetables on the organic farm, nurtured plants for the annual Mother’s Day sale and engaged with the local community at the farmers market. Before finding her place at the garden, she was part of the production and landscape installation crew at Cactus Jungle. Freddie uses her eye for aesthetics to curate her own collection of flora and loves to give flawed plants a second chance at life. She is especially interested in unusual caudiciforms, enjoying the unique quality and character of their shape. Her hands do more than lift plants all day, she is also a Certified Neuromuscular Massage Therapist.

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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 Operations

Eleanor Lonardo joined the Garden staff in October 2016. After moving to the Bay Area in 2014 the photographer-turned-gardener discovered her passion for horticulture. She started studying bio-intensive techniques and promptly turned her 5,000 sq ft backyard into a mini flower farm. Here at the Garden she oversees the infamous Forbidden Zone (our growing greenhouse) and makes sure that all of our plants on the sales floor are identified and labeled. On the weekends you can find her at various pop-up shops in the East Bay selling bouquets of flowers from her own garden.

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Cricket Riley

Landscape Design Services

Cricket joined the Garden in April 2017 after being a member for several years. One of her favorite parts of working at the Garden 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 has an AA in Landscape Architecture from Merritt College, BA in History from UC Santa Cruz, and an MA in Broadcast Journalism and Near Eastern Studies from NYU.

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Marie Gelin

Children's Education Manager

Marie joined the Ruth Bancroft Garden as a member when she first arrived to Walnut Creek 3 years ago. She became a garden docent and also guided school classes. Marie has, while she stayed at home to raise her kids, been on the boards for an HOA, a MOM's club, PTA and PTO as an officer. She is a graduate of University of Uppsala and has also studied psychology at College of the Canyons. Marie has a passion to learn new things and to share her knowledge with others. Marie believes that we learn by using all of our senses and will strive to incorporate sensory experiences into the children’s education programs. In her spare time, she enjoys gardening, jewelry making and printmaking

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Sunny Bradford

Membership Manager

A veteran human resources professional, Sunny Bradford returned to her beloved Bay Area in 2012 after living in New England for almost 14 years. Upon her return, she worked for 6 years as the Director of Learning and Organizational Effectiveness at Saint Mary’s College in Moraga, CA. Finally feeling ready to slow down (a wee bit), she began working part-time for the Napa Valley Museum as their Membership and Volunteer Coordinator. With a great fondness for nature and for succulents in particular, Sunny was delighted to join the Garden staff in June, 2019 as the new Membership Manager. Her varied interests include day-hiking, attending film festivals, and visiting museums and botanical gardens around the country. Also, she is an unabashed “foodie.”

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Banner photo by John Ricca