The American Horticultural Society’s highest award, the Liberty Hyde Bailey Award is given to an individual who has made significant lifetime contributions to at least three of the following horticultural fields: teaching, research, communications, plant exploration, administration, art, business, and leadership.

Named after Liberty Hyde Bailey (1858–1954), horticulturist, educator, author. First awarded in 1958.

Bart O'BrienThe winner of this year’s Liberty Hyde Bailey Award, Bart O’Brien, has been a leading figure in Western horticultural circles for more than four decades. “He has tirelessly promoted California native plant horticulture in particular as well as helped to conserve the state’s incredible biodiversity,” says Carol Bornstein, former director of the Nature Garden at the Los Angeles Natural History Museum. “He also is an extraordinary plantsman, with extensive knowledge of plants from California as well as other Mediterranean climate regions and beyond.”

Since 2013, O’Brien has been director of the Regional Parks Botanic Garden (RPBG) in Berkeley, California, which is part of the East Bay Regional Park District. Prior to that he spent the bulk of his career—almost 20 years—in a variety of roles at Rancho Santa Ana Botanic Garden (RSABG)—which has since been renamed the California Botanic Garden (CBG)—-in Claremont, California. At RSABG, he served as director of horticulture and director of special projects, plant introductions and sales.

“At Regional Parks Botanic Garden, Bart has been instrumental in the enhancement of the collections in this beautiful and tranquil living museum, including the development of one of the largest and most artfully constructed crevice gardens in North America,” says Randy Baldwin, president of San Marcos Growers in Santa Barbara, California.

At Rancho Santa Ana, he orchestrated the garden’s impressive fall plant sales, making an incredible array of common as well as hard to find native taxa available to home gardeners and landscape professionals alike. While Director of Special Projects, Bart helped secure grant funds to launch a satellite nursery for the garden in collaboration with the local Veterans Administration that helped train former veterans in nursery production. He co-coordinated several highly successful symposia hosted by RSABG under the title “Out of the Wild and Into the Garden,” bringing together expert horticulturists and botanists from across the state to share their knowledge. In 1999, O’Brien initiated and co-directed the Pacific Plant Promotions  program for introducing unusual plants to the gardening public, along with horticulturist Kathy Musial at the Huntington Botanical Garden and Richard Turner, who was then editor of Pacific Horticulture magazine. This program is still active.

Research and Publications

As part of his research, O’Brien has done extensive fieldwork throughout California, particularly focused on the southern inner coast ranges, San Benito County, and the eastern Mojave ranges; also in Baja California, Mexico, primarily in the California Floristic Province (from the U.S. border south to El Rosario, and adjacent Pacific islands). Major research accomplishments included being a lead author and project manager for the Checklist of the Flora of the California Floristic Province portion of Baja California, Mexico, Project, in 2011–2013, and the Rare, Endangered, and Endemic Plants of the California Floristic Province portion of Baja California, Mexico, Project, from 2009–2013.

In addition to writing or co-authoring nearly 100 articles about plants and ecology in scholarly journals and popular magazines, O’Brien served as editor of Fremontia, the scientific journal of the California Native Plant Society (CNPS) from 2006 to 2009. The publication was recently renamed Artemisia, and O’Brien remains a member of its editorial board. A highly sought-after public speaker, O’Brien also loves to share his knowledge about plants and horticulture with audiences of all kinds.

O’Brien is the co-author of three well-regarded gardening books. The first, California Native Plants for the Garden (with Carol Bornstein and David Fross), published by Cachuma Press in 2005, received the AHS’s Annual Book Award. In 2006, O’Brien collaborated with Betsey Landis and Ellen Mackey on the Care and Maintenance of Southern California Native Plant Gardens, published by the Metropolitan Water District of Southern California. Richard Turner, editor emeritus of Pacific Horticulture magazine, says the impact of this book is particularly important because of its bilingual—Spanish and English—approach, which he says, “serves to educate a portion of the state’s population that is typically ignored in garden writing. Yet, the Latino segment of our society is disproportionately involved in the garden and landscape maintenance industry despite, historically, little attempt to provide an adequate education to those whose efforts have such an impact on our urban and exurban lives.” O’Brien teamed up again with Bornstein and Fross on Reimagining the California Lawn (Cachuma Press, 2011).

Plant Explorations and Introductions

O’Brien is a renowned plant explorer who has done extensive fieldwork in California, collecting for the RPBG living collections as well as for Rancho Santa Ana. Over the course of his career, O’Brien has selected and introduced close to 40 cultivars of California native plants to the nursery trade. “He is a superb horticulturist,” says Panayoti Kelaidis, director of outreach at the Denver Botanic Garden. “He has selected numerous cultivars of salvia, manzanita (Arctostaphylos spp.), Epilobium, and a dozen other genera, many of which he showcased in a spectacular garden at Rancho Santa Ana.” One of his manzanita selections, Arctostaphylos edmundsii ‘Bart’s Beauty’, was named for him by Barbara Eisenstein, who was a colleague at Rancho Santa Ana.
Getting Started
After earning a BS in Environmental Planning and Management at the University of California, Davis, O’Brien went on to graduate from the master’s program in landscape architecture at Harvard University Graduate School of Design in Cambridge, Massachusetts. His first job in horticulture was as a landscape designer with Cambrian Nursery in San Jose, where he provided landscape consultations and designs for residential clients in the early 1980s.

After another stint as a landscape design consultant, O’Brien joined Yerba Buena Nursery in Woodside, California, in the late 1980s. Founded by Gerda Isenberg, Yerba Buena was one of the earliest retail nurseries devoted to California native plants. His experience finding and propagating plants in the wild and observing the need for more native plants in the retail nursery trade was invaluable when he made the transition to public horticulture in 1990.


In recognition of his many years of service to the California Native Plant Society, O’Brien was named a Fellow in 2018. Among the many other regional organizations, he has been active with is the Southern California Horticultural Society, where he was for many years co-chair of their speakers’ program committee and regularly conducted the plant forum at monthly meetings. He served as the organization’s president from 2002 to 2006 and was named its Horticulturist of the Year in 2005. His professional affiliations include life membership in a wide variety of plant societies, including the American Conifer Society, the Cactus and Succulent Society, the California Botanical Society, the North American Rock Garden Society, and the Society for Pacific Coast Native Iris. He has been made an honorary member of the California Garden Clubs and the Garden Club of America.

“While California’s native flora has been the primary focus of Bart’s career, gardeners, botanists, and plant lovers worldwide have been the beneficiaries of his passion for all plants,” says Turner. “Through his efforts, our own native plants and those from similar dry climates are now more widely accepted for use in private and public landscapes—a critical shift, given the changes in climate already being experienced in most of the arid West.”


Given to an individual for outstanding scientific research that has enriched horticulture and plant science. Named for H. Marc Cathey, a horticultural scientist who served as President of the American Horticultural Society for many years.

Elizabeth Mitcham

Elizabeth J. Mitcham, PhD is a Cooperative Extension Specialist and pomologist in the Department of Plant Sciences of the University of California at Davis (UC Davis), where she has been on faculty since 1992. She has also been director of the Horticulture Innovation Lab, a USAID-funded program based at UC Davis, since 2011.

Her research and Extension programs in postharvest handling of a wide array of fruit and nut crops address international issues such as food availability and safety, and offer strategies to address poverty and hunger in the world’s poorest countries. “Championing fruit and vegetables is core to her professional and personal pursuits. She has tirelessly advocated for the nutritious value of these crops and their power to fuel low-income populations with increased incomes,” says Erin McGuire, associate director of the Horticulture Innovation Lab, noting that Mitcham’s work has led to more programs helping “women, youth, and other marginalized communities.”

Elizabeth Mitcham workMitcham’s research has also focused on reducing food loss and waste. “Dr. Mitcham understands the impact on global hunger that reducing these losses could have—especially as we struggle with limited arable land and climate change impacts,” says McGuire.

Mitcham is active in professional organizations such as American Society for Horticultural Science (ASHS) and the International Society for Horticultural Science. She has served on numerous ASHS committees and is the recipient of the ASHS’s Outstanding International Scientist Career Award and its Outstanding International Horticulturist Award, among many other honors.


Given for exemplary contributions by an individual, institution, or company that demonstrate the application and value of horticulture to creating livable communities that are greener, healthier, and more equitable. First awarded in 1985 as the Urban Beautification Award; renamed for 2019.

Atiya WellsAtiya Wells is a registered nurse, outdoor educator, and the Founder/Executive Director of Backyard Basecamp, Inc.—a Baltimore-based nonprofit with a mission to (re)connect Black, Indigenous, and People of Color to land and nature. Wells is the steward of nearly 10 acres of urban farm and forest and has undertaken a multi-year project of creating BLISS Meadows, formerly a vacant lot. Described as a transformer with infectious passion and visionary leadership, Wells has demonstrated the ability to bring her community together through equitable land usage. As a result, BLISS Meadows has become a community hub which operates under the ethos of both cultural and environmental sustainability. BLISS provides a space — for young and old—to learn about nature, it creates job opportunities, connects families to the outdoor space, and provides hands on workshops for a nature-based curriculum. The initiative also provides integration and urban environmental education, health wellness programs as well as village building—deepening connections and engaging the community on regenerative cultural practices.


Recognizes significant achievements and/or leadership that have advanced the field of horticulture in America. First given in 2017. This year’s award is being given to two deserving candidates.

At her current position as supervisor at the Kemper Center for Home Gardening at Missouri Botanical Garden in St. Louis, horticulturist Daria McKelvey gets to combine her two passions: plants and teaching. She oversees the Plant Doctor and Horticulture Answer Services, which field gardening questions from homeowners, and she maintains the indoor informational displays as well as the Gardening Help and Plant Finder database on the garden’s website. She regularly gives gardening talks at the garden and at other venues for a variety of organizations.
McKelvey’s interest in plants began in childhood from time spent outdoors. After getting a degree in biology from the University of Texas in Austin, she went on to get a Master of Science in horticulture from Texas Tech University in Lubbock. One of McKelvey’s areas of expertise is Texas native wildflowers, developed during her time at Texas Tech, where she investigated techniques to enhance seed germination rates in these plants.

In addition to her work at the Kemper Center, McKelvey is a member of the St. Louis Master Gardener Association and a Master Naturalist. “Each plant, no matter where in the world, has its own story,” says McKelvey. “My goal in life is to learn those stories and share them with others.”

Sam KeitchA Pennsylvania native, Sam Keitch has worked in the public horticulture industry for over 20 years with an emphasis on production, design, and installation. He was project manager for public landscapes at the Pennsylvania Horticultural Society (PHS) for the past 10 years before recently becoming PHS’s design and procurement project manager.
A graduate of Temple University with a degree in landscape architecture, Keitch worked at the Tyler Arboretum as a gardener before coming to PHS.

As project manager, he has made an impact on the many urban green spaces in the Philadelphia area. He was involved in the design, installation, and management of landscapes along the Ben Franklin Parkway and at the Rodin Museum, Logan Square, the Philadelphia Museum of Art, and Eastern State Penitentiary, among others. He also helped design the Subaru campus in Camden, New Jersey, replacing the turf at the campus with plants that provide year-round interest as well as installing four rain gardens to create a vibrant, sustainable landscape that attracts pollinators and other wildlife.

Keitch has traveled to Germany, Italy, Portugal, and Brazil to study public landscapes in other urban settings. He also teaches workshops and runs the volunteer days at the gardens of the Eastern State Penitentiary.


This award is given to a public garden that embraces and exemplifies sustainable horticultural practices in design, maintenance, and/or programs. First awarded in 2021.

Olbrich Botanical GardenOlbrich Botanical Gardens is a major horticultural institution in Madison, Wisconsin. Spread over 16 acres are a variety of outdoor gardens featuring native Midwest plants and a conservatory filled with species from the tropics. Like many botanical gardens, Olbrich practices water-conserving techniques such as using an underground cistern to collect rainwater, establishing rain gardens, and selecting site-appropriate plants. What sets Olbrich apart is its inclusion of gravel garden technology.

According to Andrew Bunting, vice president of public horticulture at the Pennsylvania Horticultural Society, the gravel garden “approach to gardening is extremely water-wise. Essentially, the gravel replaces what would be the soil and the new plants grow through four to five inches of gravel before the roots hit the soil below. Once the gardens are established, they require virtually no watering and weeding. These gardens then become almost 100 percent sustainable with very little future inputs needed.”

This water-conserving technique is used throughout Olbrich’s outdoor gardens and in the parking lot islands. Olbrich’s former director Roberta Sladky notes that established gardens are “colorful, lush, interactive plant communities with bees, butterflies, and other pollinating and feeding insects” as well as birds that come to feast on seeds produced by “the diversity of plant specimens.”


Given to an individual or company whose innovations have made the field of horticulture more sustainable and accessible to all. New in 2022. Previously given as Luther Burbank Award, Paul Ecke Jr. Commercial Award, and G.B. Gunlogson Award.

Amigo Bob Cantisano
Photographer Marc Olivier Le Blanc

Long before organic and sustainable agriculture entered the mainstream lexicon, the late Bob Cantisano of Nevada City, California, embodied the movement. Cantisano, a self-described hippie who went by Amigo Bob, was a ninth generation Californian who embraced the organic lifestyle during his early days living in a commune. He started farming in the mid-1970s and went on to found or co-found many businesses, including Peaceful Valley Farm Supply; organizations such as the California Certified Organic Farmers; initiatives such as Organic Materials Review Institute (OMRI) and what is now the EcoFarm Conference, and helped establish legislation such as the California Organic Foods Act of 1979. In 2003, Cantisano founded the nonprofit Felix Gillet Institute, a nursery specializing in preserving 19th-century California grape and fruit and nut tree varieties from the Gold Rush era.

Wearing tie-dyed shirts, shorts, and a floppy hat, Cantisano was a popular speaker who was passionate about sharing information with growers all over the world. He cohosted a monthly radio program called Organic Matters from 1982 until his death in 2020. His wife Jenifer Bliss recalls, “Without any pre-written notes, he could stand up and talk organic farming and activism and get a huge crowd inspired to go out and change the world for the better.”


Recognizes significant contributions to the field of horticultural therapy.

Derrick StowellDerrick Stowell, PhD is education and horticulture therapy director at the University of Tennessee (UT) in Knoxville. Since taking over the UT Garden’s Horticultural Therapy Program in 2012, Stowell has worked with more than 3,600 individuals. The program serves people from a wide range of backgrounds, ages, and needs, including individuals with autism, mental health diagnoses, intellectual disabilities, and dementia.

“Derrick is a professionally registered horticultural therapist and a certified therapeutic recreation specialist,” says Leigh Starling, past president of the American Horticultural Therapy Association (AHTA). “His knowledge and skill of integrating horticulture as a therapeutic modality into his work with individuals with differing abilities touches lives on a daily basis.”

Derrick has published several articles in professional journals, including a 2018 study that describes a pilot horticultural therapy program he developed to help veterans with mental health issues. This study will be used to help other public gardens replicate the program and improve the lives of veterans in their communities. Derrick’s groundbreaking research has since been built upon by other scholars and organizations.

Derrick’s accomplishments earned him the AHTA’s Rhea McCandliss Professional Service Award in 2016. He has served on the AHTA national board of directors (2015–2018), is its current president, and has been a featured speaker at the organization’s national conferences.


Recognizes outstanding service and generosity in support of the American Horticultural Society and sustainable gardening.

Photographer Katie Garlock

Mahrou Akhundzadeh began volunteering for the American Horticultural Society in 1997. For her, River Farm and its manicured gardens evoked fond childhood memories of weekends spent at her grandfather’s house in Tehran, Iran. After moving from Philadelphia to the Alexandria area, Mahrou and her husband, Adel, became frequent visitors to River Farm and she was eventually recruited as a volunteer. While her work in the gardens was limited to one comically bad turn at pruning vines, Mahrou stayed on and helped with the now-retired Seed Exchange and has become a near-weekly presence in the Membership Department.

With an eye for color, texture, and composition honed in her Interior Design studies at Drexel University, Mahrou has enjoyed tending to her own garden and creating arrangements for residents of the Mount Vernon Nursing and Rehabilitation Center, an outreach project of the Mount Vernon Garden Club. Mahrou credits the kind and helpful staff at AHS for her longevity as a volunteer and the therapeutic power of flowers and gardens in helping her cope with the isolation of COVID and grief of personal losses.


Given to an individual, organization, or program that has inspired and nurtured future horticulturists through efforts in children’s and youth gardening. Named for Jane L. Taylor, youth advocate, horticulturist, educator.

Kimberley Lough credits her early roots of flowers, fields, and gardens coupled with her experiences living in urban settings and also abroad in a developing African nation for her deep commitment to provide opportunities for youth in low socioeconomic areas to grow their own food and experience nature.

Now in her 20th year teaching, Lough brings beauty to life for the students in her urban agriculture and Future Farmers of America (FFA) program. Her middle school agricultural program includes aqua-culture, hydroponics, vegetable and herb gardens, ornamental nursery production, and a variety of animals. Her students also compost their cafeteria’s kitchen waste and collect rainwater. The National FFA Organization selected her program as one of the Top 5 Outstanding Middle School programs three years in a row, and as a Model of Innovation in 2015. They also won 1st and 2nd place statewide honors in 2014 and 2015 in the campaign “Helping Communities Grow” sponsored by Nutrients for Life Foundation. She was also chosen as Educator of the Year for her school in 2015. Lough speaks passionately about the power of plants to transform lives and the bright future of careers available through agricultural sciences. She lends her expertise to the Seed Your Future Advisory Council.


Given to an individual whose ability to share his or her horticultural knowledge with others has contributed to a better public understanding of the plant world and its important influence on society.

Jim Klett, Hortculture and Landscape Architecture, Colorado State UniversityJames Klett, PhD has been an associate professor and Extension landscape horticulture specialist at Colorado State University (CSU) in Fort Collins since 1980. After more than 40 years, he announced his retirement last year. “Dr. Klett has excelled not only in teaching students in formal classroom settings, says Jessica G. Davis, head of the university’s department of horticulture and landscape architecture, “but also in sharing his knowledge with the general public.”

Klett is especially well-known for his “plant walks” around campus where he points out details about herbaceous plants, trees, and shrubs. He serves as co-advisor of the Horticulture Club, advisor to Pi Alpha Xi (the Honor Society for Horticulture), and has been a faculty mentor to undergraduate students in the Nursery & Landscape Management concentration as well as doctoral and master’s degree candidates.

Klett’s research focuses on landscape plant evaluation, and water requirements, weed control, and greenhouse production of landscape plants. Many of Klett’s campus research sites are open to the public, including the Annual Trial Gardens, the Perennial Gardens, and the Arboretum.

Jim Klett workKlett collaborates widely with the plant industry in Colorado and beyond and was instrumental in setting up two major initiatives: Planttalk and Plant Select. In 2017, Klett received the Best Teacher Award from the CSU Alumni Association. Other awards include Outstanding Horticulture Professor Award in 1981, 1983, 1985, and 2003; and the Pi Alpha Xi (the Horticulture Honor Society) Teacher of the Year in 2003.




The individuals, organizations, and businesses that receive these national awards represent the best in American gardening, and we applaud their outstanding achievements within their areas of expertise.