Horticultural Considerations in the Face of Climate Change

Friday, October 21 at 8:00-9:40 am, Cedar Room

Session Description: This session will discuss the strategies and solutions for native plant horticulture in the face of climate change, drought, fire, extreme storms, and other environmental challenges. We will examine the value of native plant horticulture in light of climate change.

Session Chairs: Lindsey Stuvick (Moulton Niguel Water District, Laguna Hills, CA, USA) and Ann-Marie Benz (California Native Plant Society, Cazadero, CA, USA)

15.1 Protecting the Wildland-Urban Interface in California: Native Greenbelts vs Thinning for Wildfire Threats to Homes

Greg Rubin (California’s Own Native Landscape Design, Inc., Escondido, CA, USA)

California’s unique coastal Mediterranean plant communities have evolved with adaptations to catastrophic, but infrequent fires. With ever increasing population and encroachment, fire frequency has increased dramatically, which often exposes developments along the Wildland/Urban Interface (WUI). New strategies for creating defensible space utilizing lightly irrigated native plants (along with zonal structural changes) have yielded excellent results and will be discussed. Research was conducted for the US Navy to help quantify and verify these approaches. This study utilized native chaparral and sage scrub shrubs planted in lightly irrigated greenbelts around homes to evaluate the impact on live fuel moisture content (LFMC) and predicted fire behavior. As to be expected LFMC varied markedly throughout the year being over 100% in winter in all species and treatments that included adjacent thinned native shrublands and untreated control shrublands. However, in the summer and fall there were marked differences between treatments. For most species lightly irrigated plants had the highest LFMC in the summer and fall, followed by thinned treatments and controls. These differences in moisture content, coupled with structural differences in the vegetation, contributed to expected differences in flame length and rate of spread. Lightly irrigated native shrubs planted around homes can reduce fire hazard while possessing other desirable features of utilizing native vegetation.

15.2 Tuff on Turf: Modernizing an American Icon

Audrey Pongs (Greenbelt Growers Nursery, Riverside, CA, USA)

In response to the increasing water shortage and state of drought, there is a movement to remove non-useful turf in public and commercial areas. Our goal is to express the importance of living green space and present a selection of California Native Grasses that are viable lawn replacements for commercial landscape settings. Lawns beautify public areas, making them appealing and inviting. Using adaptable native grasses and grasslike plants, we can maintain that spirit while being conscious of the environmental impacts of lawns. Mainly by reducing water and maintenance needs. We will discuss the merits, care and long term performance of a short selection of California Native grasses and sedges that have been proven suitable to landscape use. We will also introduce the idea of recreational mowable meadows, a lawn alternative that can be a valuable bridge between isolated habitats.

15.3 Emphasizing California Natives in a Water Utility’s Drought Resiliency Strategy

Lindsey Stuvick (Moulton Niguel Water District, Laguna Hills, CA, USA)

Moulton Niguel Water District provides water, wastewater, and sewer collection services to over 170,000 people in south Orange County. Since 2011, the District has provided customers with customized water budgets for their homes and businesses to support the efficient use of water. The revenue collected from over-budget consumption is collected in a Water Efficiency Fund; that money is reinvested into the community in the form of water efficiency programs to help customers use water within their water budget. Being close to the coast and a Marine Protected Area, the District and its customers value the ocean’s recreational and ecological value, so outdoor water efficiency programs incorporate a watershed approach to save water and simultaneously mitigate dry weather runoff. The District has promoted California native plants for many years, particularly plants that have a summer-dry water demand profile. California natives help us reduce overall water consumption and also reduce stress on the District’s distribution systems by mitigating peak summer demands. Additionally, they provide ecological services that are unmatched by non-native species and they’re beautiful! Due to their multiple benefits and ability to tolerate California’s periodic dry spells, the District has promoted their use and integrated them into all of its landscape related educational workshops, turf replacement programs, professional training programs, and even into a demonstration garden located at Moulton Niguel’s headquarters in Laguna Hills, CA. This presentation will detail how CA natives have become an integral part of Moulton Niguel’s drought resilience strategy and how the District has produced replicable and scalable water efficiency programs that can be adopted by other water agencies to build drought resilience in their own service areas.

15.4 Saying “Native” Last: Promoting California Native Gardens to New Audiences During Drought and Defending Their Installation During Times of Watering Restrictions. 

Scott Kleinrock (Chino Basin Water Conservation District, Montclair, CA )

Drought and watering restrictions are an opportunity to advance the wider adoption of California native plants in built landscapes, but the general public is still yet to be convinced. 

Chino Basin Water Conservation District has been actively promoting native landscapes in our community, the western urban edge of San Bernardino County, for the last five years. We continue to refine our approaches to engaging our diverse community, many of whom have absorbed drought messaging but have either never heard of native plants or do not know where to start. This talk will share what we have learned works and does not work for us in building interest in native plants through our online, in-person, and demonstration garden resources. 

We will then explore how the quantified water consumption of both newly installed and established native plantings can be used in discussions with communities, water agencies, and policy makers to promote native gardens and to defend their continued planting during watering restrictions.