Climate Ready Landscape Plants: $1 million Grant to Expand Program to Western States

The field trial at UC Davis with participants at one of the past events.
The field trial at UC Davis with participants at one of the past events.

Research by Loren Oki, lead PI, and colleagues reveals optimum low water-use landscape plants. New funding from CDFA/USDA.

A research project initiated in the Department of Plant Sciences, UC Davis, evaluates landscape plants in two-year trials under varying irrigation levels to determine the best irrigation level for optimal plant performance in regions requiring supplemental summer water. Creating water budgets is required by California’s Model Water Efficient Landscape Ordinance (MWELO), and the results from these research trials help make informed decisions when specifying, selecting, or promoting low water-use landscape plant material.

Loren Oki, Plant Sciences, UC Davis. (photo Ann Filmer)
Loren Oki, Plant Sciences, UC Davis. (photo Ann Filmer)

This year, the CDFA/USDA Specialty Crops Multistate Program funded a new Climate Ready Landscape Plants project, which will replicate the successful fields that are currently installed at:

  • UC Davis (lead PI Dr. Loren Oki and researcher Jared Sisneroz, UC Davis Plant Sciences, and Project leader Karrie Reid, San Joaquin County Cooperative Extension)
  • UC ANR South Coast Research and Extension Center (Dr. Darren Haver)

Funds from this new grant ($999,992) support the development of additional fields, under Oki's oversight, at several western universities:

  • University of Washington; Dr. Soo-Hyung Kim
  • Oregon State University; Drs. Lloyd Nackley and Ryan Contreras
  • Utah State University Center; Drs. Youping Sun and Larry Rupp
  • University of Arizona; Dr. Ursula Schuch

Conducting these new experiments on landscape plants at diverse sites across the western U.S. will reveal differences in recommendations since irrigation guidelines for landscapes vary depending on climate and soil type.

The initial project was initiated as Karrie Reid’s M.S. Thesis research in 2004, with Loren Oki as her major professor, and has been ongoing since then. Oki is a Cooperative Extension specialist and faculty member, Plant Sciences, UC Davis. Reid is now an ANR Cooperative Extension advisor in San Joaquin County.

Project descriptions, results, and images are at the UC Landscape Plant Irrigation Trials™ web site at

Related Articles from UC Davis:

  • Landscape plants for water conservation: Horticultural Research Institute funding for Loren Oki. May 2019
  • The 2018 UC Landscape plant irrigation trials. March 2018
  • How much water do landscape plants need? August 2017

(Article by Ann Filmer, Plant Sciences, UC Davis. June 29, 2020)