Determining proper zoning typically involves consideration of:

• A. Plant water needs, site microclimates, hydraulics, and topography.
• B. Color of foliage only.
• C. Soil texture alone.
• D. Annual rainfall amounts only.

Answer: (A)

Zoning focuses on grouping landscape areas that will use water similarly, so the design can deliver efficient and uniform irrigation. This relies on plant water needs to match how much water each area requires, site microclimates that create different evapotranspiration loads across the landscape, hydraulics to ensure the system can supply each zone with the right flow and pressure, and topography to account for slope-related effects on infiltration, runoff, and pressure management. The other options miss key factors: foliage color doesn't indicate irrigation demand, soil texture alone doesn’t capture water usage and distribution, and rainfall amounts alone don’t define how irrigation should be balanced with atmospheric demand.