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Grant Johnson

Assistant CE Urban Agriculture Technology Area Advisor
South Coast Research & Extension Center
7601 Irvine Boulevard
Irvine, CA 92618
gejohnson@ucanr.edu Create VCard

Also in:
Orange County - UC Cooperative Extension
Los Angeles County


Grant Johnson serves as the Urban Agriculture Technology Advisor for Los Angeles and Orange Counties, providing impartial, research-driven insights to optimize plant production in urban environments. With a focus on indoor production, such as greenhouses, his diverse clientele includes nurseries, commercial growers, school districts, and community gardens. In his dynamic role, Johnson actively shapes the future of urban agriculture by tackling challenges through economies of scale. This involves creative exploration of horticultural topics related to irrigation, plant culture, and agricultural technology innovations that drive the future of farming, ensuring technological advancements that benefit a wide range of urban farming practitioners.


M.S. Horticulture and Agronomy, University of California Davis. 2023
B.S. Biological Sciences, California Polytechnic State University San Luis Obispo. 2013


Irrigation management, horticulture, nursery crops, indoor production, urban agriculture

Areas of Expertise (click to see all ANR academics with this expertise)


Peer Reviewed

  • Pitton, B. J. L.; Wikramanayake, A. M., et al. (2023). Mechanically-Incorporated Controlled-Release Fertilizer Results in Greater Nitrogen and Salt Leaching Losses from Soilless Substrate in Containers. Horticulturae. 9:42.
  • Redekar, N., T. Bourret, J. Eberhart, G.E Johnson, B.J.L. Pitton, D.L. Haver, L.R. Oki, J. Parke. The population of oomycetes in a recycled irrigation water system at a horticultural nursery in southern California. Water Research, 2020, 183, 1–10.

  • Pitton, B.J.L., G.E. Johnson, D.L. Haver, L.R. Oki. Water use and estimated evapotranspiration at a California container plant nursery. Full text article for International Symposium on Irrigation of Horticultural Crops. Acta Horticulturae, 1335, 82

  • Pitton, B. J.L., L.R. Oki, D.L. Haver, G.E. Johnson. The payoff of recycling nursery water. American Nurseryman, 2017, 21-23

Non-Peer Reviewed

  • Spinelli, Gerry; Johnson, Grant (2023). Why Pressure Drops as Water Flows in a Pipe and Other Irrigation Mysteries. Summer Extension Connection Newsletter.R. Padilla. University of California Cooperative Extension. August, 2023. https://cesandiego.ucanr.edu/newsletters/Extension_Connection_Newsletter98783.pdf

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