I’ve had a Rachio 2nd Gen installed for about two years now near Sacramento, CA. My zones include lawn, shrubs with spray sprinklers and drip for shrubs and trees. I initially setup the system up using Rachio defaults and recommendations for each zone type. After losing a number of plants on the drip system due to insufficient watering (no visual indication that anything is running until the plant dies), I switched to manual settings, which stopped the die-off, but doesn’t seem to be very efficient in the use of water. I’ve started exploring how to improve the watering cycles but am overwhelmed at the level of detail required to “do it right”.
The information that is required to properly configure each zone based on the recommendations here is extremely difficult to obtain, varies from location to location in the zone and changes over time. The base soil type of my area is not the type of soil that was put on top after the house was constructed. I know neither the source or type of the top soil and in some areas, it is different than in others.
The root depth varies by size, age, type of plant and the depth of topsoil above the prevalent hard pan. The hard pan is nearly sandstone and is not porous at all, but is also not contiguous throughout the yard. When plants are installed, they are in potting mix and depending on the size of the root ball, the transition zone of potting soil/native soil blend varies greatly. And then complicating one zone’s effectiveness, there is a line of about 15 Italian Cypress trees along the fence line that suck up a significant amount of the irrigation water, making it difficult to grow shrubs without apparently over-watering.
Regarding the crop coefficient, Rachio says, " Each vegetation or plant type has a different crop coefficient, which is used in determining evapotranspiration. The higher the coefficient number, the more water the plant uses." A typical suburban yard that is artfully landscape has many different types and sizes of plants. It is not agricultural irrigation.
While I understand the use and value of approximations, I don’t see any reasonable way, meaning that I don’t want to make watering my yard my life’s work, of configuring the zones other than the way I did it with a mechanical controller. Basically, run times are increased until there’s standing water or run-off and decreased until the plants starting wilting in-between cycles. The only value I see to a “smart controller” is to turn it off when rain is forecast and the cycle and soak feature to improve penetration during a single cycle.
I’d appreciate thoughts on striking a balance between the time spent to develop a detailed map of all of these parameters throughout the seasons and making good use of a smart controller with a reasonable expenditure of my time.