Nursery Production of Local Ecotype Seed in Support of
Regional Restoration Efforts
Brianna D. Borders1, Patrick A. Kelly1, Nur P. Ritter1 and Kenneth D. Lair2
1 California State University, Stanislaus, Endangered Species Recovery Program, Turlock, California 95382
2 Environmental Applications and Research Group, Bureau of Reclamation, Denver, Colorado 80225
Background Seed Harvest and Processing
In the San Joaquin Valley of California, large-scale conversion of Plant material was harvested by hand, transported to a seed
native lands to agricultural and urban uses has resulted in processing facility, and air-dried. Small or fragile seed lots were
widespread impacts to ecosystems and biodiversity. However, cleaned by hand. But for most seed lots, a hammer mill was used
many thousands of acres of farmland in the valley trough are to reduce raw plant material into a coarse but uniform mixture of
drainage-impaired and ill-suited to irrigated cultivation. seeds and chaff. Seeds were then separated from chaff using wire
Consequently, under the Central Valley Project Improvement Act of mesh sieves, an air density separator1, a Clipper Eclipse2, and a
1992, a Land Retirement Program—managed by U.S. Department of Clipper Office Tester2.
Interior’s Bureau of Reclamation, U.S. Fish and Wildlife Service,
and Bureau of Land Management—was established to purchase
impaired farmlands from willing sellers.
With appropriate habitat restoration, including revegetation with
native species, some retired lands could potentially contribute to
the recovery of some of the many endangered and threatened
species in the region. However, local genotypes of San Joaquin Seeds of Phacelia tanacetifolia, Castilleja exserta, and Salvia columbariae (from left to right) photographed
through a dissecting microscope. Scale is 1 cm.
Valley native plants are largely unavailable from commercial seed
suppliers, and the amount of seed that could be responsibly 1SeedTech Systems 2The A.T. Ferrell Company
collected from areas of native habitat would be insufficient for
reseeding large tracts of retired farmland.
In response to this lack of native Challenges Encountered
seed availability, the CSU
Stanislaus, Endangered Species Non-native weed species are prevalent at the nursery and
Recovery Program established a throughout the retired agricultural lands. Weed growth at the
native plant seed production nursery was controlled through a combination of mechanical
program, with support from the (tilling, flaming, hand-pulling) and chemical (pre and post-
Land Retirement Program. Seed emergent herbicides) measures. The nursery site has an arid
production activities were climate, with average annual precipitation of 22.03 cm (8.67 in).
conducted at a 1 to 3 hectare field Precipitation is highly variable both spatially and temporally and
nursery located near Tranquillity, can limit plant growth and seed production. Herbivorous
Location of the native plant field nursery
California and a seed processing mammals including black-tailed jackrabbits, desert cottontails,
facility located in Fresno, CA. and deer mice regularly feed on nursery-grown native plants,
reducing potential seed harvest. Outbreaks of false chinch bugs,
a pest insect associated with non-native mustard plants, have
periodically impacted plant health and survival.
Seed Collection and Planting
Seeds of over 100 species have been collected from native plant
populations located within an 80-km radius of the nursery site.
For seven consecutive growing seasons (2001-2008), wild- Summary of Accomplishments
collected seeds were planted at the nursery. Seeds were hand Identified numerous areas of remnant native vegetation within
sown onto planting beds in October or November, before the onset an 80 km radius of the nursery site that can provide a source of
of fall and winter rains. local ecotype seed
Compiled observations on the phenology (germination,
flowering period, seed collection window) of over 75 San
Joaquin Valley natives
Submitted 42 seed lots (of 36 species) to the National Center
for Genetic Resources Preservation, a seed archiving facility
Compiled a photo database of species at various life stages
(seed, seedling, mature)
Phacelia ciliata, Monolopia stricta, and P. tanacetifolia
Alkali sink habitat from which seeds were collected
(from left to right) in cultivation at the nursery Produced ~545 bulk kg (1200 lbs) of seed per growing season
Identified a suite of species that are relatively easy to cultivate,
reliably produce seed each year, and have high potential for
adaptation to site conditions of the retired agricultural lands:
To avoid shifts in population genetic composition and to maintain Allenrolfea occidentalis Hemizonia pungens
genetic variability, we sought to exclude bias from our selection of Atriplex polycarpa Lasthenia chrysantha
seed stock.1 We did not use any dormancy-breaking treatments to Atriplex spinifera Madia elegans
enhance germination.1 Plants were not fertilized and we did not Frankenia salina Phacelia ciliata
Grindelia camporum Phacelia tanacetifolia
use any soil amendments. Plants were not watered on a regular
Isocoma acradenia Wislizenia refracta
basis, though the nursery was occasionally flood irrigated in
response to seasonally low rainfall. Seeds were collected from
entire planted populations without regard to plant size, vigor, or
seed output.2 Whenever possible, we collected seed on multiple
dates during the collection window, in order to capture both early
and late maturing genotypes.2,3 Nursery-produced seed was not
re-planted for more than four successive generations.4 However,
competition from weed species was reduced through continuous
weed removal efforts. Trichostema ovatum, Malacothrix coulteri, and Salvia columbariae (from left to right) have been
cultivated at the nursery.
Literature Cited Acknowledgments
1Meyer,S. E., and S. B. Monsen. 1992. Genetic considerations in propagating native shrubs, forbs, and grasses from seed.
Funding for this project is provided by the United States Department of Interior’s Land Retirement Program. We thank
Pages 47-54 in Proceedings of the Western Forest Nursery Association Meeting. General technical report RM-221. U.S.
Stephen Lee (U.S. Bureau of Reclamation) and Bea Olsen (U.S. Fish and Wildlife Service) for their role in overseeing the
Forest Service, Fort Collins, Colorado.
nursery contract. For their many hours of hard work at the nursery and at the seed processing warehouse, we thank
2McKay, J. K., C. E. Christian, S. Harrison, and K. J. Rice. 2005. "How local is local?" - A review of practical and conceptual numerous past Endangered Species Recovery Program (ESRP) staff members. We thank a crew of agricultural technicians
issues in the genetics of restoration. Restoration Ecology 13:432-440. that provided assistance with seed processing and all aspects of nursery-based work. We thank the California Department of
3Knapp,E. E., and K. J. Rice. 1994. Starting from seed: genetic issues in using native grasses for restoration. Restoration Fish and Game for granting us permission to collect seed from several of their properties and for allowing us to store
and Management Notes 12:40-45. equipment at the Mendota Wildlife Management Area. We thank Robert Jones for assistance with irrigation and tractor work.
We thank John Stebbins and Catherine Sayers for the use of greenhouse space on the California State University, Fresno
4Smith,S. L., A. A. Sher, and T. A. Grant. 2007. Genetic diversity in restoration materials and the impacts of seed collection campus.
in Colorado’s restoration plant production industry. Restoration Ecology 15:369-374.