Determining the ideal run time for Rain Bird sprinklers depends on several factors, including the type of sprinkler, the output rate, the type of vegetation being watered, and weather conditions. With some key information, you can optimize your sprinkler runtimes to provide your lawn and landscaping with sufficient water without overwatering or wasting water.
What Type of Rain Bird Sprinkler Do You Have?
Rain Bird offers a wide variety of sprinkler models for both residential and commercial use. Each sprinkler type has a different precipitation rate, area of coverage, and optimal operating pressure. Some common Rain Bird sprinkler types include:
- Rotary sprinklers – These sprinklers rotate back and forth to spray water over a set area. Rotary spray nozzles are available in different arc patterns from 40 degrees to 360 degrees.
- Spray heads – Spray head sprinklers distribute water in a fan pattern through a nozzle. They are available in various spray distances from 4 feet to over 30 feet.
- Impact sprinklers – Impact sprinklers use a swinging arm to distribute water through one or more nozzles. They typically cover a medium to large area.
- Gear drive rotors – Gear drive rotors have a gear-driven mechanism to rotate the sprinkler head and distribute water over a circular pattern. Rotor sprinklers can cover anywhere from 25 feet to over 70 feet.
- Micro-irrigation – Micro-irrigation emitters like inline dripline and micro-spray jets provide low volume, targeted watering for gardens and landscaping beds.
The precipitation rate, spray distance, and arc pattern of your specific sprinkler will determine how long to run each sprinkler zone.
Measure the Flow Rate
The flow rate, also called the precipitation rate, is the amount of water distributed by a sprinkler over a set time period, usually measured in gallons per minute (GPM) or inches per hour (in/hr). Rain Bird provides precipitation rate specifications for all its sprinkler models to help determine runtimes.
If you do not have the manufacturer precipitation rate for your sprinklers, you can measure the rate yourself by performing a catch can test:
- Place empty tuna cans or similar containers in a grid pattern within one sprinkler zone.
- Run the sprinkler zone for a set amount of time, such as 15 minutes.
- Measure the amount of water in each can, in inches.
- Calculate the precipitation rate by dividing the amount of water by the run time. For example, if the cans collected 1 inch of water in 15 minutes, the precipitation rate is 1 inch per 15 minutes, or 0.5 inches per hour.
Repeat this test to measure the precipitation rate for each type of sprinkler head in your irrigation system.
Determine Your Watering Needs
The amount of water your landscape requires depends on factors like:
- Plant types – Turf grass, annual flowers, perennials, and shrubs have different water needs.
- Root depth – Plants with deeper roots require less frequent watering.
- Soil type – Sandy soils drain faster than silty or clay soils.
- Weather and climate – Hot, dry, or windy conditions create higher water demand.
- Microclimates – Shady areas or sheltered locations may need less water.
Check with your local nursery or extension office for watering recommendations based on your plant types, soil, and climate. Most gardens and lawns need about 1 to 1.5 inches of water per week from either rainfall or irrigation during the growing season.
Set Sprinkler Run Times
To determine the ideal run time for each valve zone, follow these steps:
- Identify the types of sprinklers in each zone and look up or measure the precipitation rates.
- Determine your peak season weekly watering needs in inches.
- Divide your weekly need by the number of watering days per week to get the depth needed per watering.
- Divide the depth needed by the precipitation rate to find the runtime. For example, if you need 0.5 inches per watering at a precipitation rate of 1 inch per hour, run the zone for 30 minutes (0.5 inches divided by 1 inch/hour = 0.5 hours or 30 minutes).
Runtimes may need to be adjusted seasonally as plant water needs decrease, or split into multiple cycles to avoid runoff on slopes and clay soils.
Consider Weather Conditions
Be sure to adjust sprinkler run times based on current weather. After rainy periods, reduce watering to avoid oversaturation. In hot, dry, or windy weather, increase runtimes to compensate for faster evaporation.
Smart irrigation controllers can automatically adjust watering schedules based on weather. Or you can manually reduce runtimes after substantial rainfall (over 0.5 inches) and increase as needed during heat waves.
It is also best to water in the early morning hours before sunrise to minimize evaporation loss. Avoid watering in the evening or at night, as wet foliage increases disease risk.
Watch for Signs of Over or Under Watering
Monitor your landscape regularly for signs you may need to adjust sprinkler run times:
- Wilting, drought stress – Increase watering time.
- Puddles, water runoff – Reduce watering time.
- Turf not springing back when walked on – Increase time.
- Mushy areas, footprinting in lawn – Decrease time.
- Leaf scorch on trees and shrubs – Increase time.
- Mildew, fungal disease – Reduce frequency.
Make gradual time adjustments of 5 to 10 minutes per zone until you achieve the desired results.
Perform Regular Maintenance
Keep your Rain Bird sprinklers operating efficiently with regular maintenance:
- Inspect sprinklers occasionally for blocked nozzles, broken heads, and alignment issues. Clean clogged nozzles and replace damaged components.
- Adjust sprinkler heads as needed to provide optimal coverage without overspray onto pavement.
- Monitor and adjust pressure regulators and valves for proper pressure.
- Winterize the system each fall by draining pipes and lines.
- Have a professional perform an annual system inspection and tune-up.
Proper maintenance will maximize sprinkler performance and prevent issues like leaks, malfunctions, and water waste.
Use an Irrigation Schedule
An irrigation schedule tailored to each zone and adjusted across the seasons ensures sprinklers provide the right amount of water when plants need it most to remain healthy and reduce waste. Here are some schedule tips:
- Water early in the morning, before 10 am if possible.
- Water 2-3 days per week in short cycles to reduce runoff.
- Adjust schedule monthly or seasonally based on weather and plant needs.
- Program multiple start times to prevent runoff on slopes and clay soils.
- Water shrubs and perennials 1-2 times per week, lawns 2-3 times per week.
- Increase frequency during hot, dry periods; reduce after rainy spells.
Utilizing rain sensors or smart controllers can take out the guesswork by automatically adjusting watering based on weather.
Consider Alternatives to Sprinklers
For water-wise irrigation, consider supplementing sprinklers with:
- Drip irrigation – Drip systems deliver water slowly and directly to plant root zones, avoiding waste from overspray, runoff, or evaporation.
- Soaker hoses – Porous soaker hoses seep water slowly into soil and are ideal for gardens and shrub beds.
- Micro-sprinklers – Micro-spray jets, bubblers, and misters provide targeted, low flow watering for gardens.
- Rain barrels – Rain barrels capture roof runoff for reuse in gardens and landscaping.
Combining sprinklers, micro-irrigation, and rain harvesting creates an efficient irrigation plan that waters based on each area’s needs.
Conclusion
Optimizing Rain Bird sprinkler run times takes some legwork upfront to measure precipitation rates and determine plant water needs. But this effort pays off with healthy landscapes and greater water savings over time. The key is monitoring and adjusting run times across the seasons as conditions change. Investing in an efficient irrigation controller simplifies this process by automatically adjusting watering schedules as needed. With the right run times dialed in, Rain Bird sprinklers will deliver sufficient water to keep landscapes thriving without runoff or waste.