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Gerry Spinelli Horticulture Advisor

Gerardo (Gerry) Spinelli is the new Production Horticulture Advisor serving the Nursery and Floriculture industry in San Diego. Gerry conducts applied research, extension, and education to improve viability and profitability of the Nursery and Floriculture industry, while conserving natural resources and complying with regulations. The Nursery and Floriculture industry in San Diego county is the first in California for volume of sales and the second in the US.

Gerry’s primary interests are irrigation management and water quality. These themes are a primary concern for growers given the high cost of water and the pressure from local and state water quality regulators. Nitrogen management is another of the advisor’s interests, given its strong relation to water management and its importance in the environmental impact of horticultural industry.

Pests, particularly invasive ones are another pressing issue for the industry. With the large volumes of ornamentals moving in and out from other states (primarily Florida and Hawaii), San Diego is particularly exposed to this threat.

Gerry is also interested in other themes unique to San Diego county, including urban agriculture and horticulture in the rural-urban interface and food deserts in low-income areas. Local growers face issues urban development encroaching into rural areas increasing the cost of real estate and the competition for water.

Nursery and Floriculture growers in San Diego county have shown the great ability to quickly react to these forces and adapt production practices to keep the industry profitable. Gerry’s primary concern is to conduct a research and extension program that serves the industry in present and future challenges.

Additional Information

To see my Education and Publications, click here:





My program focuses on water and nitrogen management in horticultural container production, hydroponics, and greenhouses. Water management includes improving the efficiency of irrigation water application, water distribution uniformity and correct scheduling of irrigation events. It also includes irrigation runoff, storm water management, nitrate and sediment management and erosion control. In nursery and floriculture production, the value of the crop is represented by its aesthetics. Producing beautiful plants requires high levels of water and nitrogen and production is often intensive. Nitrogen management becomes an issue given the high solubility of nitrate that can pollute groundwater and surface water bodies.