Advancing Puget Sound Native Plant Propagation

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Though our ongoing study “Advancing Puget Sound Native Plant Propagation,” the SER-UW Native Plant Nursery aims to advance native plant production and interest in Western Washington native plants with a unique combination of research, education, and outreach. Through this study, our nursery aims to advance native plant production efficiency and effectiveness by analyzing and reporting multiple years of propagation data, developing online resources for nursery professionals, strengthening industry connections, and expanding communications about the benefits of planting native plants.

Project Justification

The United Nations has named the years 2021 through 2030 the “Decade of Ecosystem Restoration.”¹ There is a global recognition of the power of ecological restoration in combating climate change and empowering environmental justice. The fuel for ecological restoration is plant material, especially the plants native to a region. However, restoration agencies and landscape designers routinely identify a lack of commercial availability as a significant barrier to their use of locally-adapted species.² The struggle of native plant nurseries to meet local demand is due to several factors, including a lack of species-specific expertise. For example, resources around stratification, scarification, germination rates, and growth phase duration are limited and inconsistent, complicating efforts to efficiently schedule native plant crops. 

Since 2019, the SER-UW nursery team has been recording detailed methods for stratification, scarification, and germination rates for a wide range of species. In the Fall of 2022, we also began tracking the duration of growth phases. This project aims to summarize our historical propagation trials, conduct new propagation trials, and invest time into outreach to ensure our findings reach relevant industry and community stakeholders. Our project will increase the understanding of stratification and scarification requirements and the duration of growth phases, allowing nurseries that propagate native plant species from seed to increase the scale of their production, reduce inefficiencies, and meet demand for native plant material. 

Assessment

In the initial stages of this study, we sought the expertise of industry professionals to guide our research efforts around native plant production. We asked industry professionals to identify the needs and preferences of their organization regarding native plant production. Our research team received twenty-six (26) responses to our Western WA native plant nursery industry survey.

Download a copy of the full report. 

The responding nurseries represent a spectrum of native plant suppliers, from those who strictly sell native species to those who carry only a limited supply of PNW natives (Figure 1). Our survey respondents expressed that, in general, they are growing the native plants that they sell rather than sourcing them for other suppliers or wild harvesting them (Figure 2). Only 24% of the responding nurseries stated that they grow “None” or “Very Little” of the native plants they sell. Whereas 60% reported that they grow “Most” or “All” of the native plants they’re selling.

We asked nurseries to identify if their primary method of native plant production was either sexual reproduction (growing from seed) or vegetative reproduction (growing from cutting, division, etc.).The respondents were split nearly down the middle, with 10 nurseries reporting sexual reproduction as their primary method and 11 nurseries reporting vegetative reproduction as their primary method (Figure 3).

Our survey identified a variety of barriers nurseries face in fulfilling native plant orders. Figure 5 is a list of responses, ordered from most to least frequently expressed by respondents. A strong majority of respondents listed a variation of insufficient inventory or lack of availability as their greatest barrier. Similarly a mismatch in available species (supply) and requested species(demand) was also reported. Combining these two barriers, we find that 44% of the responding nurseries struggle with some sort of lack of availability (Figure 5).

Across 22 responses, 32 distinct species were identified as species nurseries would like additional propagation information (Appendix A). Additionally, five genera were identified with no particular species. An analysis of responses yields little consensus on species to research further, with the most common response being Vaccinium parviflorum, with a total of three mentions. No other species received more than two mentions, with most receiving only one (Figure 6). Our research team cross-referenced two propagation protocols, the Native Plant Network database and the UW Plant Propagation Protocols (ESRM 412), to determine if the identified species were represented in either database. All species except for Paxistima myrsinites were represented in either one or the other database. 

Batch 1

Based on the results of our industry survey, our research designed three batches of priority species. Batch 1 focuses on: Vaccinium parviflorum, Vaccinium ovatum, Taxus brevifolia, Myrica gale, and Arctostaphylos uva-ursi.