Samples of Irrigation Schedules

Many homeowners request irrigation schedules to help them program their traditional controllers. Any schedule provided needs to be adjusted based on the type of watering device, soil, slope and plants.

The right controller, when properly scheduled, can result in significant water savings and lower water bills. The goal of an efficient watering schedule is to irrigate only the amount of water that is needed by the plant. Most landscapes are over-watered by as much as 50 percent more water than what the plants need.

Sample Seasonal Watering Schedules - Contra Costa County

Note: Your irrigation system may need more or less time based on weather conditions, soil type, slope and performance; distribution uniformity, precipitation rates (spray or drip).

You can save literally thousands of gallons of water on your landscape, and save your plants from drowning, just by ensuring the proper settings of your irrigation controller. But you can't just set it and forget it - to get those savings; you need to change the watering schedules with the changing seasons.

Programming your controller:

1. Set the current time and day and replace the back-up battery that holds the program memory.

2. Start with program A for your lawn areas. Group stations or valves that require the same watering frequencies together on the same program.

3. Select each station and enter the minutes of watering time for each valve.

4. Select the time you'd like your irrigation to start. You can have 2 or 3 different start times per day. Program start times should be one or more hours apart to allow the water to soak in and prevent run-off.

5. Select the days you want your irrigation to run, making sure you don't water on the same day you mow the lawn.

6. Program A is complete. Use programs B & C for other zones that require less water, such as ground covers, shrubs, low water use plantings, etc.

Definitions:

SPRING - The season of growth! March, April and May are considered the months of spring in California. Typically plants start to require supplemental water from irrigation systems during these months.

SUMMER – Always the warmest season. June, July, and August are considered the months of summer. Our summers have average maximum daily temperatures that range from 84 to 90 degrees, with maximum temperatures going over 100 degrees. Your garden will need the most amount of water in this season.

FALL – The season of decreasing plant water needs. September, October, and November are considered the months of fall. The peak temperatures in September may be close to summer temperatures, but reduced day length and the sun being lower in the sky means greatly reduced plant water needs. Plants only require approximately 50% of their peak need in September and only 25% of peak need by November in Central and Eastern Contra Costa County.

WINTER - The season of short days and lowest temperatures. December, January, and February are considered the months of winter. Rainfall normally takes care of any water requirements for your landscaping during this period. Colder temperatures slow plant growth and eliminate the need for additional water from irrigation systems. It is very important to turn your controller off during these months. In dry years supplemental water might be needed as early as February.

NUMBER OF DAYS ON: Typical irrigation controllers allow a program to be scheduled to operate any day of the week. Operation can happen on any number of selected days. Adding or subtracting days is a common way to adjust controllers for increasing or decreasing seasonal water requirements. Multiple Programs A, B, and C, allow you to run different valves on different days with different run times.

MINUTES PER STATION: Each station or valve is given a run time in minutes that is determined by the amount of time it takes for water to saturate the soil and start running off. A typical time for water to run off in clay soils with a spray system is 5 minutes. This is the maximum amount of watering time that you should apply to allow the soil to absorb the water. This is known as "Cycle and Soak". Apply water and allow time for it to soak in before applying additional required water.

START TIMES: Each program in the controller has two to four start times depending on the model of the irrigation controller. Repeated start times allows for the "Cycle and Soak" principle by giving time for the water to be absorbed into the soil and thereby avoid run-off . If we need 10 minutes of watering, per day, then we would use two start times one hour apart with a 5 minute station run time each. Start times for different programs should not conflict with each other.

TOTAL MINUTES PER WEEK: The suggested watering schedules are based on the average historic weather data and corresponding monthly irrigation requirements. We assume the irrigation system is well designed and maintained. Your individual irrigation system may apply water faster or slower based on the design, type and spacing of sprinkler heads. Also, significant differences in temperatures can occur throughout the year that are out of the monthly averages. For these reasons YOU MAY HAVE TO ADJUST UP OR DOWN to meet the watering needs of your lawns and landscaping.