Current Projects

SHRE Proposals funded for 2024-2025

Title	Evaluating state-listed Hoover’s bent grass as a native turfgrass and its potential for horticultural introduction into the landscaping and nursery trades (continuation)
Primary Investigator	Christina Varnava, Principal Investigator and Living Collections Curator, Santa Barbara Botanic Garden
Project Summary	California’s native grasses are a vital part of the landscape, yet they are underrepresented in the horticultural trade. Currently, there are only 50 grasses and grass relatives (e.g. Carex, Juncus) listed as “commonly available” on Calscape.org (Calscape 2024). Compare this with data from the California Invasive Plant Council which has 52 species of invasive grasses on their list of noxious weeds (Cal-IPC.org). These include many grasses that are commonly sold in nurseries such as purple fountain grass (Pennisetum setaceum) and pampas grass (Cortaderia selloana). There is a compelling need to make more species of California native grasses available for consumers. The proposed project will continue work to evaluate best practices to establish California state listed S2 grass Agrostis hooveri (Hoover's bent grass) for introduction to the horticultural trade. We will trial A. hooveri alongside other commonly used California native grasses to understand the performance of this grass under a variety of cultural conditions. The project’s scope of work includes planting Agrostis hooveri seed collected from wild populations as outlined by our 2023 proposal, and evaluating its performance when subjected to common stressors (e.g. shade, drought). The project will also help to continue our work to conserve this state-listed rare species.

Title

Evaluating state-listed Hoover’s bent grass as a native turfgrass and its potential for horticultural introduction into the landscaping and nursery trades (continuation)

Primary Investigator

Christina Varnava, Principal Investigator and Living Collections Curator, Santa
Barbara Botanic Garden

Project Summary

California’s native grasses are a vital part of the landscape, yet they are underrepresented in the horticultural trade. Currently, there are only 50 grasses and grass relatives (e.g. Carex, Juncus) listed as “commonly available” on Calscape.org (Calscape 2024). Compare this with data from the California Invasive Plant Council which has 52 species of invasive grasses on their list of noxious weeds (Cal-IPC.org). These include many grasses that are commonly sold in nurseries such as purple fountain grass (Pennisetum setaceum) and pampas grass (Cortaderia selloana).

There is a compelling need to make more species of California native grasses available for consumers. The proposed project will continue work to evaluate best practices to establish California state listed S2 grass Agrostis hooveri (Hoover's bent grass) for introduction to the horticultural trade.

We will trial A. hooveri alongside other commonly used California native grasses to understand the performance of this grass under a variety of cultural conditions. The project’s scope of work includes planting Agrostis hooveri seed collected from wild
populations as outlined by our 2023 proposal, and evaluating its performance when subjected to common stressors (e.g. shade, drought). The project will also help to continue our work to conserve this state-listed rare species.

Title

Pumice and coconut-derived peat (Coir) as primary components of media for
propagation and cultivation of low-water-use drought adapted plants

Primary Investigator

Ernesto Sandoval, Graduate Student MS program Horticulture and Agronomy Graduate Group, UC Davis

Project Summary

This project will test various grades of pumice combined with Coir test their effects on the growth rate of various species of succulents such as CA native Agave, Dudleya, Sedum, and various Cacti, as well as non-native Cacti and South African Aloes that are suitable for use as low-water landscaping plants in California. The purpose of this project is to optimize growth rates of seedlings and cuttings/tissue cultured plant material in the early stages as would be desirable in the nursery industry as well as enthusiasts. As part of this research, I will experiment with novel methods of layering media to further test for methods of optimal culturing of succulents which typically suffer from overwatering/insufficient root oxygen in conventional container media. The results of this research will be disseminated as published research as well as outreach through lectures and workshops to Cactus and Succulent clubs and incorporated into Master Gardener trainings that I regularly lead.

This project addresses SHRE’s Current Research Priority 3: “Test new ideas and
innovative cultivation and/or management practices related to plant tolerance to climate change ...” Although the use of Pumice is popular as a major component in succulent plant cultivation, its use has not been quantified under any comparative experimental conditions. Furthermore, research on the benefits of media layering is limited and non-existent for succulents. This project will help elucidate the maximum benefits of easily measurable and repeatable combinations of Pumice and Coir in terms of air-filled porosity (AFP) in conjunction with water (WHC) and nutrient-holding capacity (CEC).

SHRE Proposals funded for 2023-2024


Title	Evaluating state-listed Hoover’s bent grass as a native turfgrass and its potential for horticultural introduction into the landscaping and nursery trades
Primary Investigator	Christina Varnava, Principal Investigator and Living Collections Curator, SBBG
Project Summary	Few species of California native grasses are commonly available in the ornamental horticultural trade, despite their diversity in the wild, with only 50 of 644 species listed as “commonly available” on the Calscape website (Calscape 2023), as compared to the California Invasive Plant Council’s Inventory (Cal-IPC) which lists 52 species of invasive grasses. Disappointingly, many species in Cal-IPC's inventory are plants that are still commonly available in the horticultural trade, especially purple fountain grass (Pennisetum setaceum) and pampas grass (Cortaderia selloana). A clear need exists to create more diversity in California native ornamental grasses available to consumers, helping consumers satisfy their aesthetic preferences and also make plant choices that benefit the habitats and wildlife around them. The proposed project will evaluate best practices to propagate and establish California state listed S2 rare grass Agrostis hooveri (Hoover's bent grass) for introduction to the horticultural trade. The project’s scope of work includes collecting Agrostis hooveri seed from remaining populations in Santa Barbara and San Luis Obispo Counties, discover effective methods of propagation, and establish outplantings at SBBG to evaluate its performance as a native turf replacement for non-native ornamental grasses. The project will also help to conserve a state-listed rare native species.

SHRE Proposals funded for 2022-2023


Title	Climate Resilient Gardening Offers Solutions to Drought Impacts Affecting Western Ornamental Horticulture
Primary Investigator	Sarah Beck, Executive Director, Pacific Horticulture
Project Summary	According to the March 22 U.S. Drought Monitor, 100% of California is in drought, with 36.8% in extreme (D3) or exceptional (D4) drought. California residents, gardeners, horticulture, and allied professionals have an existential interest in strengthening our community’s capacity to withstand climate-related hazards including drought. Climate resilient gardening offers solutions. Pacific Horticulture will exponentially amplify drought resilient gardening through programs and new media channels. By highlighting regional research and connecting gardeners with knowledge and tools they need, the introduction of shade trees, California natives, or other drought-tolerant plants suitable for landscape use in California can build adaptive response. Pacific Horticulture is uniquely positioned to engage with scientists to interpret and deliver the results of critical horticultural research via accessible science communication channels. Our reach extends to an audience of gardeners, horticulture and allied professionals who reside in California and have a stated interest in native and drought resilient plants and related practices. Pacific Horticulture builds on a track record of providing resources on the ways drought impacts affecting western ornamental horticulture can be mitigated. Examples include educational articles and videos, live events, Q&A sessions with experts, curated discussion platforms, and regional resources.


Title	Scaling the California Native Plant Landscaper Certification Program
Primary Investigator	Andrea Williams, Director of Biodiversity Initiatives, California Native Plant Society
Project Summary	As the pace and impacts of climate change accelerates, and drought conditions across the state of California grow more extreme, our state and local governments are now faced with drastic reductions in water use—especially water used in outdoor landscaping. While native plant landscapes require very little supplemental water, and are highly drought-tolerate, they require special care in selection, maintenance, and care—information that is largely unknown or unavailable in the landscape industry. It’s clear that, for more low-water, sustainable native plant gardens and landscapes to thrive in our state, we need better education and trainings for landscape professionals. To this end, the California Native Plant Society (CNPS) will launch our California Native Plant Landscaper Certification Program, a new initiative that will help connect landscape and garden professionals with the skills, experience, and professional accreditation they need to plant, maintain, and care for native plant landscapes. Building on a successful pilot project in Los Angeles, our team will now launch a Bay Area-focused program in Northern California. In the year ahead, our program will train five (5) sets of 30 landscape and gardening professionals throughout Northern California, two (2) sets in Spanish and three (3) in English. Feedback and experience from this project will guide additional training needs and educational practices. Professional lists of Certified landscapers will then be made available locally for consumers in need of landscape services.


Title	A Glass 60% Full: Landscaping to Conserve Water and Reduce Fire Hazards in Northern California
Primary Investigator	Leimone Waite, Horticulture Instructor, Shasta College
Project Summary	Shasta College and its surrounding communities in far northern California, have experienced significant drought and massive wildfires that have had significant impacts on plant survival and landscape. Shasta College is proposing to offer four public workshops, free of charge, to residents in collaboration with the Shasta County Master Gardeners (SCMG). Through these workshops, which will be videotaped and made available online for free public access, homeowners will learn practical, long-term solutions to help maintain their existing landscapes and help transition to more sustainable, water-conserving options. Educational workshops will cover best practices in effective irrigation, how to convert existing irrigation systems, how to add graywater systems, lasagna composting, and how to landscape to reduce or mitigate fire hazards. SCMG volunteers will identify and compile a list of Shasta County climate-appropriate, fire- resistant plants that will be distributed at the workshops, a weekly Farmers Market booth, and will be downloadable at no cost from the SCMG website. All videos and materials will be made available statewide to Master Gardener Groups to share with the public in their counties.