Rancho Santa Ana Botanic Garden: 75 Years Promoting Knowledge, Conservation, and Landscape Use of California’s Native Flora

By: Clem Hamilton Bart O’Brien

Bart O’Brien is one of Southern California’s most highly respected native plant specialists and co-author with David Fross and Carol…

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Susanna Bixby Bryant

Susanna Bixby Bryant

Every so often, one encounters an historical figure whose prescience is so startling as to suggest that she had the benefit of time travel. Such a figure is Susanna Bixby Bryant, who founded Rancho Santa Ana Botanic Garden in 1927, as a “botanical garden where California natives reign supreme.”

Born in 1880, Susanna Bixby spent her formative years on her family’s Rancho Los Alamitos in southern California (see Pacific Horticulture, Summer ’89). The story is told that when little Susanna was ill, her doting father, John W Bixby, led her pony into the house to her bedside, much to her delight and, one presumes, the consternation of the rest of the household.

The family moved to Berkeley after Susanna’s father’s death in 1887. Her schooling took her to Boston, followed by travels to Europe and elsewhere. Back in California, Susanna caught the eye of Dr Ernest Albert Bryant, personal physician to railroad tycoon Henry Huntington (who was in the early stages of creating his own museum and botanic garden in San Marino), and they were married in 1904.

After her mother’s death in 1906, Susanna found herself co-proprietor, with her brother Fred, of their childhood ranch plus another, Rancho Santa Ana. She took an active role in the ranch’s management, planting citrus, walnuts, pears, and pomegranates, and experimenting with other crops (from grapefruit to lychee) that she believed had potential in southern California.

Susanna had been impressed in 1915 by renowned plantsman Theodore Payne’s all-native landscape in Exposition Park and corresponded with him in 1925 about creating a botanic garden featuring exclusively California native plants on her ranch. Encouraged, she sought counsel from Harvard’s Charles Sprague Sargent, who provided further stimulation while cautioning that attempting to grow “every kind of wild plant” native to the state would present insurmountable horticultural challenges. In words that shape the Garden’s culture to this day, she replied to his concerns that, “I am going to compromise by going ahead with my original scheme.”

She did so in 1927, planting a 165-acre portion of Rancho Santa Ana according to a design by University of Southern California landscape architect Ernest Braunton and a plant list compiled by John Thomas Howell, a student of UC Berkeley taxonomist Willis Jepson, one of Susanna’s primary correspondents.

As if she could see to the present day, when over a thousand taxa of California’s natives would be rare and/or in danger of extinction, Susanna stressed conservation first and foremost: “our primary object is to preserve our native California flora, try to replenish the depleted supply of some of our rarest plants, and bring together . . . as complete a collection of the rich store of native California plants as can be made to grow in this southern section of the State.” Lest that conjures an image of a simple-minded “Noah’s ark,” Susanna stressed “scientific value” and included an herbarium, botanical library, and service to students and scholars.

In 1934, Susanna established an endowment to ensure the Garden’s future and assembled a five-member board of trustees. The living collection, herbarium, and library grew and, in 1948, the premier volume of the Garden’s research journal, El Aliso (named for southern California’s ubiquitous riparian sycamore, Platanus racemosa), appeared featuring Garden botanist Carl Wolf’s encyclopedic work on New World cypresses (Cupressus).

When Susanna passed away unexpectedly in 1946, Garden botanist Philip Munz became director. He and the trustees recognized that the Garden’s remote location prevented sufficient access for public visitation and research. After considering alternative sites, the trustees chose Claremont, for its proximity to the Claremont Colleges, where Munz had been a faculty member. The Garden purchased fifty-four acres, entered into an agreement with Pomona College on the perpetual use of thirty-plus acres of College land, and moved to today’s eighty-six-acre site in 1951.

Research continues as the Garden’s programmatic backbone, with Aliso having reached nineteen volumes and the graduate program (in conjunction with Claremont Graduate University) having awarded over ninety master’s and PhD degrees. The research endeavors are highlighted by decades-long service from such renowned scholars as Munz, horticulturist and director Lee Lenz, biosystematist Verne Grant, mycologist Richard Benjamin, anatomist Sherwin Carlquist, and taxonomist Robert Thorne. Current researchers (Travis Columbus, Elizabeth Friar, and Mark Porter) continue the Garden’s tradition of research across the breadth of plant systematics. Professors Carlquist and Thorne have received the Asa Gray Award from the American Society of Plant Taxonomists, making the Garden the only institution to be so honored twice. The herbarium has surpassed one million specimens, and its staff conducts Californian floristic and phytogeo- graphic research.

During Thomas Elias’s directorship, the Garden helped establish the Center for Plant Conservation, a national consortium of gardens and organizations dedicated to the conservation of plant diversity. The Garden’s long-term freezer storage today preserves seeds of 279 taxa of plants listed as rare or endangered by the California Native Plant Society; 101 of those, plus 100 more, are represented in the living plant collection. Staff also conducts monitoring, inventory, and population biology research on rare plants, and has begun to assist land managers in the reintroduction of plants to the wild.

In the past twenty-five years the Garden has greatly increased its public programs and accessibility. Today it welcomes 5000 schoolchildren on organized tours, approximately 1000 adult participants in community education classes, and over 70,000 visitors per year; 200 volunteers provide 17,000 hours of service to the Garden annually.

The Cultivar Garden, with a pink selection of California buckeye (Aesculus californica 'Canyon Pink'), a bright yellow x Parkinsidium 'Desert Museum', and a deep blue Salvia 'Carl Nielson'. Photographs by Bart O'Brien

The Cultivar Garden, with a pink selection of California buckeye (Aesculus californica ‘Canyon Pink’), a bright yellow x Parkinsidium ‘Desert Museum’, and a deep blue Salvia ‘Carl Nielson’. Photographs by Bart O’Brien

Living Collections and Horticulture

Since its inception, the Garden has assembled over 20,000 living plant accessions, of which the vast majority are documented collections of seeds or cuttings gathered from native populations of Californian plants. From a horticultural perspective, perhaps the most influential facet of the Garden’s holdings is the collection of Californian cultivars, which consists of wild documented individuals, chance seedlings and hybrids of garden origin, selections from controlled hybridization experiments, and, in the case of annuals and short-lived perennials, named seed strains. This collection also includes a number of trademarked and patented plants (but not yet any genetically engineered California cultivars).

The bright flowers of Keckiella ‘Dick Straw’ sparkle against Salvia clevelandii ‘Winifred Gilman’

The bright flowers of Keckiella ‘Dick Straw’ sparkle against Salvia clevelandii ‘Winifred Gilman’

Through its history, the Garden has selected numerous highly regarded plants. Staff have named and introduced 115 cultivars, including annuals, herbaceous perennials, succulents, shrubs, and trees, in twenty-seven genera: Amsinckia (1), Arctostaphylos (19), Baccharis (4), Ceanothus (14), Cercis (1), x Chiranthofremontia (1), x Chitalpa (2), Encelia (2), Fragaria (2), Fremontodendron (4), Helianthus (1), Heteromeles (1), Heuchera (7), Iris (29), Justicia (1), Keckiella (3), Mahonia (1), Mimulus (1), Opuntia (2), Penstemon (2), Rhus (1), Ribes (4), Salvia (7), Solanum (1), Stenocereus (1), Umbellularia (1), and Epilobium [including Zauschneria] (2).

Ribes sanguineum var. glutinosum ‘Claremont’

Ribes sanguineum var. glutinosum ‘Claremont’

Many Garden cultivars have achieved prominence, among them Arctostaphylos ‘Emerald Carpet’ and ‘Pacific Mist’; Baccharis pilularis var. pilularis ‘Twin Peaks #2’; Ceanothus ‘Frosty Blue’; C. griseus ‘Santa Ana’; Fremontodendron ‘California Glory’, ‘Pacific Sunset’, and ‘San Gabriel’; Heuchera ‘Opal’, ‘Santa Ana Cardinal’, and ‘Wendy’; Mahonia ‘Golden Abundance’; Ribes sanguineum var. glutinosum ‘Claremont’; and Salvia ‘Allen Chickering’.

Rancho’s first cultivar was selected and named in 1937 after its discoverer and Garden trustees’ chair, Allen Chickering, who found it on a morning walk in the Garden. The plant was a hybrid sage (Salvia clevelandii x S. leucophylla) with beautiful, large, blue-violet flowers. Though that individual was never vegetatively propagated, a subsequent nearly identical plant was selected around 1949 and released in 1955 as Salvia ‘Allen Chickering’. It continues to be widely grown and appreciated throughout California.

From 1949 until 1983, Lee Lenz studied the genus Iris and named twenty-nine selections. Of these, his most recognized success was Iris ‘Sierra Sapphire’, which won the prestigious Sydney B Mitchell Award in 1977. Unfortunately, the Garden no longer has any of these iris cultivars in its collection. (The authors would very much like to hear from anyone who still grows these fine plants.)

Since its introduction in 1959, Baccharis pilularis ‘Twin Peaks #2’ (usually sold as ‘Twin Peaks’) has been grown by the tens of thousands, and is the most commercially successful plant the Garden has produced. Cuttings of this prostrate male plant were originally collected from Twin Peaks in San Francisco by Percy Everett and EK Balls in 1956.

Fremontodendron ‘California Glory’ above Encelia californica ‘El Dorado’

Fremontodendron ‘California Glory’ above Encelia californica ‘El Dorado’

Fremontodendron ‘California Glory’ is the Garden’s most well traveled introduction, grown around the world. ‘California Glory’ was selected by Everett and was named and released in 1962. It won an Award of Merit from the California Horticultural Society (exhibited by Strybing Arboretum) in 1965, and a First Class Certificate from the Royal Horticultural Society (exhibited by the director of Wisley) in 1967.

During the past decade, many of the Garden’s introductions have been selected for today’s smaller gardens. None of these plants will grow much taller than six feet (and most are much smaller): Arctostaphylos auriculata ‘Diablo Blush’, A. edmundsii ‘Big Sur’, A. stanfordiana ‘Sonoma’, Encelia californica ‘El Dorado’, Heuchera elegans ‘Bella Blanca’, H. parishii ‘Chiquita’, Penstemon spectabilis ‘Snow Dragon’, Ribes malvaceum ‘Dancing Tassels’, R. malvaceum var. viridifolium ‘Ortega Ruby’, Salvia clevelandii ‘Betsy Clebsch’, S. ‘Starlight’ and ‘Vicki Romo’, Solanum parishii ‘Purple Haze’, and Epilobium ‘Route 66’ and ‘Summer Snow’.

White-flowered bush anemone (Carpenteria californica) behind Heuchera ‘Genevieve’

White-flowered bush anemone (Carpenteria californica) behind Heuchera ‘Genevieve’

Of particular note to California native plant gardening enthusiasts are Rancho’s horticultural publications. The Garden’s first horticultural publication, in 1938, was a serial titled Leaflets of Popular Information. The full run of seventy-three numbers though 1944 was written by botanist Carl Wolf and provided the foundation for Lenz’s 1956 book, Native Plants for California Gardens. Percy Everett’s 1957 book, A Summary of the Culture of California Plants at the Rancho Santa Ana Botanic Garden 1927-1950, provided a unique and thorough view of the Garden’s living collection at its original site. In 1981, Lenz collaborated with John Dourley to write the authoritative California Native Trees & Shrubs For Garden & Environmental Use In Southern California And Adjacent Areas. The desire to publish proceedings of the Garden’s horticultural symposia, Out of the Wild and Into the Garden, gave impetus to the creation of a new Garden serial publication: Rancho Santa Ana Botanic Garden Occasional Publications. Three volumes of horticultural symposia and two floras were published in this series in the 1990s. Two additional volumes of symposium proceedings will appear shortly.

The Future

The Garden’s seventy-fifth anniversary sees southern California’s urban sprawl continuing to push its wildlands into ever diminishing islands. Therefore gardens like Rancho Santa Ana, and other conservation-minded organizations, face challenges of an acuteness and urgency that would shock even Susanna Bixby Bryant, who so clearly perceived the significance of the trends she saw in the early twentieth century.

It is the Garden’s responsibility, in fulfilling Susanna’s vision, to ambitiously promote a world in which California’s plant diversity is well documented and understood; where plant taxa do not face extinction or substantial reduction in their genetic and ecological diversity; and with urban landscapes that are attractive, resource-efficient, esthetically Californian, and free of exotic plants that invade native habitats.

Horticulturally, this means making the landscape use of native plants commonplace, not just the province of dedicated aficionados, as it largely is today. Of the plants currently sold in the “mass market” of the Southern California landscape trade, far fewer than one percent are native to this region. Our successors will gauge our success by the degree to which we increase that number.