Crop Coefficients for Landscape Plants

Schedules & Zones Flex Daily
1

Where can I look up Crop Coefficients for various plants? I am particularly interested in Arizona Xeriscape plants.

I understand the concept, but have no idea what a particular plant’s value would be. Googling has so far only found some values for farming crops at a couple of locations. In this forum I see various posts indicating to adjust the coefficient to value x, but I don’t know if x was obtained from a data table or is based on trial and error.

If I have a zone with various shrubs, each with a different crop coefficient, would you use the highest coefficient, lowest, or an average?

I am in Arizona midway between Phoenix and Tucson (Casa Grande), and it looks like Arizona typically needs adjustments from the default values. Only 8 hours of sun? How does our excess UV factor in?

2

Rachio does list Xeriscape as a plant option, but doesn’t break it down further. Online research should give you more specific values.

Different shrub types in the same zone is always a problem: some will be under-watered, while others will be over-watered. Usually an average isn’t bad. I add a 2 minute sprinkle in the heat of the day for my wife’s flowers when they’re blooming.

The Crop Evapotranspiration value with Flex Daily should take care of the sunshine and UV factor; the question in Rachio is mostly to determine if shade is caused by trees or structures.