University of California

Field trials identify more native plants suited to urban landscaping


S. Karrie Reid
Lorence R. Oki

Authors Affiliations

S.K. Reid is UC Cooperative Extension (UCCE) Junior Specialist, Department of Plant Sciences and Department of Landscape Architecture, UC Davis; L.R. Oki is UCCE Specialist, Department of Plant Sciences and Department of Landscape Architecture, UC Davis.

Publication Information

Hilgardia 62(3):97-104. DOI:10.3733/ca.v062n03p97. June 2008.

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There is a growing need in the state of California for landscape plants that require fewer inputs of water and chemicals. To address this issue, a program was initiated at UC Davis to test the landscape potential of California native plants not currently in widespread horticultural use. Ten unused or underused California native plants were screened in open-field conditions for low water tolerance during summer 2006. In all cases, there were no significant differences in the summer growth or physical appearance between four irrigation levels. Six species maintained a favorable appearance throughout the season and were advanced to demonstration gardens in seven climate zones throughout the state, where Master Gardeners are performing further assessments on their performance. These irrigation and climate zone trials are part of an ongoing program coordinated by UC Cooperative Extension, the UC Davis Arboretum and the California Center for Urban Horticulture to introduce more low water-use and low chemical-use plants through partnerships with the commercial horticultural industry.


Anella LB, Schnelle MA, Maronek DM. Oklahoma proven: A plant evaluation and marketing program. HortTechnol. 2001. 11(3):381-4.

Armitage AM, Green M. The university trial garden as a tool for evaluating and introducing new plant materials. HortTechnol. 2001. 11(3):368-72.

Bailey HC, Deanovic L, Reyes E, et al. Diazinon and chlorpyrifos in urban waterways in Northern California, USA. Env Toxicol Chem. 2000. 19:82-7. https://doi.org/10.1897/1551-5028(2000)019

Brenzel KN. Sunset Western Garden Book (8th ed.). 2007. Menlo Park, CA: Sunset Pub. 768p.

[CalEPA] California Environmental Protection Agency. State Water Resources Control Board. 2007. Water Quality. Irrigated Agricultural Waivers Program. www.waterboards.ca.gov/agwaivers/index.html .

Costello LR, Matheney NP, Clark JR. A Guide to Estimating Irrigation Water Needs of Landscape Plantings in California. 2000. The Landscape Coefficient Method and Water Use Classification of Landscape Species. UC Cooperative Extension and California Department of Water Resources. www.owue.water.ca.gov/docs/wucols00.pdf .

Dunwell WC, Fare D, Arnold MA, et al. Plant evaluation program for nursery crops and landscape systems by the Southern Extension and Research Activities/Information Exchange Group-27. HortTechnol. 2001. 11(3):373-5.

Hanak E, Davis M. Lawns and water demand in California. Cal Econ Pol. 2006. 2(2):1-24. Public Policy Institute of California, San Francisco, CA.

Irmak S, Haman DZ, Irmak A, et al. Measurement and analyses of growth and stress parameters of Viburnum odoratissimum grown in a multi-pot box system. HortScience. 2004. 39(6):1445-55.

Lindstrom JT, Robbins JA, Klingaman GL, et al. The University of Arkansas Plant Evaluation Program. HortTechnol. 2001. 11(3):362-4.

Mackay WA, George SW, Davis TD, et al. Texas Superstar and the Coordinated Educational and Marketing Assistance Program (CEMAP): How we operate. HortTechnol. 2001. 11(3):389-91.

Padilla FM, Pugnaire FI. Rooting depth and soil moisture control Mediterranean woody seedling survival during drought. Functional Ecol. 2007. 21(3):489-95. doi:10.1111/j.1365-2435.2007.01267.x https://doi.org/doi:10.1111/j.1365-2435.2007.01267.x

Pooler MR. Plant breeding at the US National Arboretum: Selection, evaluation and release of new cultivars. HortTechnol. 2001. 11(3):365-7.

[USNA] US National Arboretum. Web Version of the USDA Plant Hardiness Zone Map. 2006. USDA Misc Pub No 1475, 1990. www.usna.usda.gov/Hard-zone/index.html .

Weston DP, Holmes RW, You J, Lydy JJ. Aquatic toxicity due to residential use of pyrethroid insecticides. Env Sci Technol. 2005. 39(24):9778-84. doi:10.1021/es0506354 https://doi.org/doi:10.1021/es0506354

Wilen CA., Robinson G., Osborn S. Survey of residential pesticide use in an urbanized area of Southern California. HortScience. 2001. 36(3):613-

Reid S, Oki L. 2008. Field trials identify more native plants suited to urban landscaping. Hilgardia 62(3):97-104. DOI:10.3733/ca.v062n03p97
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