Approximate Running Time: To provide your lawn with 1 inch of water per week, run your spray sprinklers for about 2 hours weekly, ideally split into three 20-minute sessions in early mornings.
On average, a lawn needs 1 to 1½ inches of water a week. It usually takes 1 hour of watering to get 1 inch of water, so it's best to figure out how to distribute watering sessions over the week. In normal conditions, water your lawn in three 20-minute sessions over the week.
2. Spray sprinkler heads can apply 1 to 2 inches of water per hour and can usually run 6 to 8 minutes before runoff occurs. If your system applies 2 inches per hour, set your timer one day a week for five 6-minute cycles with an hour in between for absorption.
For example, rotor sprinkler heads might require 20 to 30 minutes of straight watering time, while a traditional spray head zone will only need 5 to 10 minutes.
The ideal watering schedule is once or twice per week, for about 25 to 30 minutes each time. Taking care of a lawn doesn't have to be an overwhelming, all-consuming task.
Your sprinklers apply one inch in 20 minutes. This means you need to water 40 minutes per week. Divide the 40 by 7 and round up. This means that you should run your sprinklers about 6 minutes per day.
However, the exact amount of time your sprinkler system runs will depend on the type of nozzle. High-flow nozzles may require 15 minute sessions, while low-flow nozzles may require around 45 minutes of watering.
To keep your lawn green and growing, it needs about 1 inch of water per week from you, rainfall or a combination of both. To measure how much is 1 inch of water, set a group of flat-bottomed cups at 5- to 10-foot intervals from the base of your sprinkler to the edge of its reach.
Therefore, an “inch of water” is 0.62 gallons per square foot of garden area. Unless you use a gallon jug to water a square foot garden, this number may still leave you wondering how to obtain that inch of water or 0.62 gallons per square foot.
Nothing should be in that area between the bottom of the sprinkler heads and the imaginary horizontal plane parallel to the ceiling that is 18 inches below. This is done to allow an even and unobstructed spray pattern from the sprinklers when triggered to extinguish the fire.
The average usage of water in a residential sprinkler system is between 12 – 30 gallons per minute depending on the type and size of the sprinkler head.
According to lawn care experts, the best time to water grass is in the early morning, ideally before 10am. During this time, the temperature outside is still relatively cool, and the wind and sun are less intense.
(Note: This Formula Comes From Precipitation Rates And Sprinkler Irrigation – Student Manual, (3/6/96) Courtesy Of Hunter Industries, San Marcos, CA.) = . 96 in./hr.
To make sure your lawn is getting enough water, place empty tuna cans in the areas you are watering and stop when they fill to 1-1.5 inches. (Alternatively, you can buy a permanent rain gauge to monitor precipitation or test your watering.) This can take 15-30 minutes, depending on what you use to water.
If it is not raining, the lawn can need as much as 1 hour for rotor zones and 10-15 minutes on spray zones. We recommend watering 3-4 times per week. If you still notice dry spots, we recommend supplemental watering in between regularly scheduled water times.
Your goal is for the lawn to receive enough water to keep the soil slightly moist in the upper six inches of soil. This usually requires at least one inch of water per watering session or around 30 minutes of watering, however, each lawn is different.
Lawn Watering Practices
Frequent watering encourages shallow root growth and unhealthy grass. Deep, less frequent watering encourages grass roots to grow deeper into the soil reservoir from which to draw moisture. Deep roots also mean the lawn will be less affected by surface drying.
Generally, most lawns need about 1 inch of water per week, including rainfall. This typically means running your irrigation system for about 1–2 hours per week, depending on its type and delivery rate.
1-2-3-2-1 watering technique:
In April water 1 day/week. In May ramp up to 2 times/week. In the heat of the summer water 3 times/week. In September drop back to 2 times/week. In the fall drop back down to 1/week.
If the soil is dry an inch beneath the surface, your garden probably needs watering. We also find it helpful to keep the following watering formula in mind: 1 inch of water per 1 square foot = 0.62 gallons.
If you're not sure how much time it takes for your sprinklers to spray an inch of water, you're not alone. A fixed spray head nozzle might take ~30 minutes to apply 1 inch of water, whereas a rotary nozzle could take 3x as long to apply the same amount.
Spray nozzles (such as the Rainbird MPR nozzles), use a constant fan of water and put down water the fastest, with a precipitation rate (sometimes matched) of 1.5 – 3.0 inches (38 – 75 mm) per hour, depending on the spray radius and coverage design. Generally, these can run up to 15 minutes per watering.
Your lawn needs 1 to 1 ½ inches of water per week. A typical in-ground sprinkler system provides ½” of watering, per zone, in a half an hour. This would mean that you need to run each zone of your sprinkler system for 30 minutes, 3 times a week to sufficiently hydrate your lawn.