Watering guide

Keep it green—without wasting blue

You don’t need a green thumb to keep your grass healthy. Simply follow this guide.

This guide assumes heavy clay soil, which is the most common in IRWD’s service area. Additionally, keep in mind that the watering times suggested are the maximum amount of time you’ll need for full sun areas.

Start with this schedule and adjust the times only if your plants show signs of stress. If stress occurs only in isolated areas, check the operation of your irrigation system before adjusting times.

The guide recommends “cycling and soaking” your landscaping. “Cycle and soak” means that your sprinklers turn on for a period of time, then turn off to allow the water to soak in, and finally turn back on again. This is a better way to water because it eliminates water run-off and allows water to soak deeper into the roots of your plants, resulting in healthier root growth.

Please consult your irrigation controller owner’s manual for simple instructions on “cycling” your watering schedule.

Spray head irrigation schedule

For standard spray head irrigation systems

The following chart suggests a weekly schedule for spray head irrigation, assuming heavy clay soils common to most local coastal and foothill areas. Generally, these are the MAXIMUM times you will need for full sun areas. Start with this schedule and increase the times only if your plants show signs of stress. If stress occurs in isolated areas, check your irrigation system for leaks or coverage gaps before increasing watering times.

Download PDF for more information
Spray head irrigation chart

En Espanol
Horarios de riego por goteo

Horario de riego semanal sugerido

Wondering what the percentages are about? Some irrigation controllers allow you to adjust the amount of water by adjusting a seasonal percentage control. You can automatically reduce all of your watering schedules by 30% if you have that option on your controller.

Spray Head Irrigation Schedule
MonthTurfgrassDrought tolerant trees, shrubs & groundcover% Option**
January2 days, 2 cycles of 2 minutes1 day, 2 cycles of 3 minutes30%
Febuary2 days, 2 cycles of 2 minutes1 day, 2 cycles of 3 minutes30%
March3 days, 2 cycles of 3 minutes2 days, 2 cycles of 3 minutes50%
April3 days, 2 cycles of 4 minutesh2 days, 2 cycles of 4 minutes70%
May3 days, 3 cycles of 3 minutes2 days, 3 cycles of 3 minutes80%
June3 days, 2 cycles of 5 minutes2 days, 3 cycles of 3 minutes90%
July4 days, 3 cycles of 3 minutes2 days, 3 cycles of 4 minutes100%
August4 days, 3 cycles of 3 minutes2 days, 3 cycles of 4 minutes100%
September*4 days, 2 cycles of 3 minutes2 days, 3 cycles of 4 minutes70%
October*3 days, 2 cycles of 3 minutes2 days, 3 cycles of 3 minutes50%
November*2 days, 2 cycles of 3 minutes1 day, 2 cycles of 4 minutes40%
December2 days, 2 cycles of 2 minutes1 day, 2 cycles of 3 minutes30%

* In September, plants’ water needs drop by approximately 30 percent even if the temperature is hotter, because the days are shorter, so evaporation decreases. Also, plants are entering a dormant phase where they need less water. In some years, humidity is also higher, increasing your level of discomfort, but decreasing plants’ water needs as it slows the rate of evaporation. This rapid drop in water needs will continue in October and November.

** The % option, set with either a button or a dial, permits the watering run times for all irrigation system valves managed by an electronic controller to be increased or decreased with just one adjustment by percentage.

Inline emitter dripline systems

Standard Dripline System – 12” & 18” Emitter Spacing

Download PDF for more information
RAINBIRD XFD systems
RAINBIRD XFDEmitter spacing 18”
Row Spacing 18”
0.6 GPH/PR=0.43”		Emitter spacing 12”
Row Spacing 18”
0.9 GPH/PR=0.96”		% Option**
MonthDrought Tolerant Plants
(Moderate Water Use Kc = .5)		Drought Tolerant Plants
(Moderate Water Use Kc = .5)
January1 day, 1 cycle of 50 minutes1 day, 1 cycle of 22 minutes30%
Febuary1 day, 1 cycle of 56 minutes1 day, 1 cycle of 25 minutes30%
March2 days, 1 cycle of 39 minutes2 days, 1 cycle of 17 minutes50%
April2 days, 1 cycle of 47 minutes2 days, 1 cycle of 21 minutes70%
May2 days, 1 cycle of 56 minutes2 days, 1 cycle of 25 minutes80%
June3 days, 1 cycle of 37 minutes3 days, 1 cycle of 16 minutes100%
July3 days, 1 cycle of 38 minutes3 days, 1 cycle of 17 minutes100%
August3 days, 1 cycle of 39 minutes3 days, 1 cycle of 17 minutes100%
September*2 days, 1 cycle of 48 minutes2 days, 1 cycle of 2 minutes70%
October*2 days, 1 cycle of 27 minutes2 days, 1 cycle of 16 minutes50%
November*1 day, 1 cycle of 54 minutes1 day, 1 cycle of 24 minutes40%
December1 day, 1 cycle of 44 minutes1 day, 1 cycle of 20 minutes30%
RAINBIRD XFD systems
RAINBIRD XFDEmitter spacing 18”
Row Spacing 18”
0.4 GPH/PR=0.43”		Emitter spacing 12”
Row Spacing 18”
0.6 GPH/PR=0.65”		% Option**
MonthDrought Tolerant Plants
(Moderate Water Use Kc = .5)		Drought Tolerant Plants
(Moderate Water Use Kc = .5)
January1 day, 1 cycle of 72 minutes1 day, 1 cycle of 33 minutes30%
Febuary1 day, 1 cycle of 80 minutes1 day, 1 cycle of 37 minutes30%
March2 days, 1 cycle of 56 minutes2 days, 1 cycle of 26 minutes50%
April2 days, 1 cycle of 67 minutes2 days, 1 cycle of 31 minutes70%
May2 days, 1 cycle of 81 minutes2 days, 1 cycle of 37 minutes80%
June3 days, 1 cycle of 53 minutes3 days, 1 cycle of 24 minutes100%
July3 days, 1 cycle of 55 minutes3 days, 1 cycle of 25 minutes100%
August3 days, 1 cycle of 56 minutes3 days, 1 cycle of 26 minutes100%
September*2 days, 1 cycle of 69 minutes2 days, 1 cycle of 32 minutes70%
October*2 days, 1 cycle of 52 minutes2 days, 1 cycle of 24 minutes50%
November*1 day, 1 cycle of 78 minutes1 day, 1 cycle of 36 minutes40%
December1 day, 1 cycle of 63 minutes1 day, 1 cycle of 29 minutes30%

* In September, plants’ water needs drop by approximately 30 percent even if the temperature is hotter, because the days are shorter, so evaporation decreases. Also, plants begin to go into a dormant phase where they need less water. In some years, humidity is also higher, increasing your level of discomfort, but decreasing plants’ water needs as it slows the rate of evaporation. This rapid drop in water needs will continue in October and November.

** The % option, either a button or a dial, permits the watering run times for all electric valves managed by a controller to be increased or decreased with just one adjustment by percentage.

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