How to Water a Colorado Lawn
Learn the 1-2-3-2-1 Lawn Watering Technique
A Lawn Watering Technique Designed by Science
-Promotes the grass roots to grow deeply
–Stimulates beneficial microbial activity in the soil
-Prevents lawn diseases like Necrotic Ring Spot and Ascochyta Leaf Blight
-Saves water
–Prevent grub infestations in the lawn (if grub eggs dry out they will die)
-Designed for both the health of the lawn and the trees
-The 1-2-3-2-1 watering technique is designed based on logic and science
What Time of Day is Best for Lawn Watering?
The ideal time to water a lawn is early in the morning, before the sun rises. It is best to program the sprinkler system so that the last zone finishes as close to 6:00 AM as possible. If this isn’t feasible, the next best option is to water the lawn in the late evening. When watering deeply and infrequently, evening watering should not lead to lawn fungus problems in Colorado’s dry climate.
Programming the clock to end around 6:00 AM can be a bit challenging. First, you need to add up the total run time for all the zones. Then, subtract that total time from 6:00 AM. While this may sound straightforward, calculating time can be more complex than it seems.
Why is Early Morning the Best Time of Day to Water a Lawn?
- Cooler Temperatures: During these hours, temperatures are cooler, and there is less evaporation, so more water is absorbed by the soil and roots.
- Calmer Winds: Mornings often have less wind, reducing water loss due to wind drift.
- Healthier Grass: Watering early allows the grass blades to dry shortly after the sun rises, reducing the risk of diseases like fungus that thrive in wet conditions.
Each Zone’s Programming Time is
Based on 2 Main Factors:
#1 Sun Exposure & #2 Style of Head
Two key factors are essential for setting each zone’s sprinkler times correctly: the sun angle (north, south, or east/west facing) and the type of sprinkler heads used in each zone. It’s common for each zone to have different programmed times, which can vary significantly. For example, a north-facing pop-up zone might be programmed for 6 minutes of watering, while a south-facing rotary zone could be programmed for 55 minutes.
Every sprinkler system is unique and depends greatly on its design and installation quality. The sprinkler zone time chart below can provide a useful starting point for programming your sprinkler clock. To achieve optimal accuracy, it is best to measure the output of the sprinkler system using rain gauges or have Organo-Lawn perform a sprinkler audit for your system. Note: Our technicians do not measure your sprinkler system’s output, but our technicians have a lot of experience with programming clocks correctly.
Note: Adjustments to sprinkler run times might be necessary based on overlap and nozzle output.
Program Each Zone Based on the Style of Head and Sun Exposure
Rotary Style
Sprinkler Heads
Rotary-style heads are designed to water large areas of grass efficiently. They move back and forth slowly, which requires longer watering times.
Sun Exposure:
Full Sun or South Facing Aspects:
50-60 minutes total run time
Approximately 3/4 inch of water
Partial Sun or East / West Aspects:
40-50 minutes total run time
Approximately 1/2 inch of water
Full Shade or North Facing Aspects:
30-40 minutes total run time
Approximately 1/3 inch of water
Popup Style Sprinkler Heads
Popup-style heads are designed to irrigate smaller areas of grass. They are stationary and deliver a large amount of water in a short period of time. This design requires shorter watering durations.
Sun Exposure:
Full Sun or South Facing Aspects:
18-20 minutes total run time
Approximately 3/4 inch of water
Partial Sun or East / West Aspects:
12-15 minutes total run time
Approximately 1/2 inch of water
Full Shade or North Facing Aspects:
6-10 minutes total run time Approximately 1/3 inch of water
MP Rotator Style Sprinkler Heads
MP Rotator-style heads are designed to water grass gradually. They feature a pinwheel action that allows water to soak deeply into the soil. For proper lawn hydration, they require longer run times.
Sun Exposure:
Full Sun or South Facing Aspects:
45-55 minutes total run time
Approximately 3/4 inch of water
Partial Sun or East / West Aspects:
35-45 minutes total run time
Approximately 1/2 inch of water
Full Shade or North Facing Aspects:
25-35 minutes total run time
Approximately 1/3 inch of water
Impact Style
Sprinkler Heads
Impact-style sprinkler heads are designed to irrigate large areas of grass. They move back and forth very slowly and require longer watering times to ensure the lawn is watered deeply.
Sun Exposure:
Full Sun or South Facing Aspects:
45-60 minutes total run time
Approximately 3/4 inch of water
Partial Sun or East / West Aspects:
35-50 minutes total run time
Approximately 1/2 inch of water
Full Shade or North Facing Aspects:
20-35 minutes total run time
Approximately 1/3 inch of water
Micromist Style Sprinkler Heads
Micromist-style heads are designed to water plants in rock and mulch bed areas. They spray a mist over plants and require medium run times to water deeply.
Sun Exposure:
Full Sun or South Facing Aspects:
35-45 minutes total run time
Partial Sun or East / West Aspects:
25-35 minutes total run time
Full Shade or North Facing Aspects:
15-25 minutes total run time
Drip Irrigation System
Drip systems are intended to operate for one hour. The water flow from the drip lines is not controlled by a timer but should be regulated through the emitters.
Each Drip Emitter is Rated by Gallons per Hour (GPH)
- Small plants require a 1/4 to 1/2 GPH emitter
- Shrubs require a 1 to 7 GPH emitter
- Trees require a 10 to 35 GPH emitter installed.
Therefore, the gallons per hour should not be controlled via the clock but via the emitters and the GPH rating.
***However, many sprinkler installers do not fully grasp this concept. If you find a better time based on the emitters installed at your property, we recommend that you use that time instead.***
Full Sun or South Facing Aspects:
60 minutes total run time
Partial Sun or East / West Aspects:
60 minutes total run time
Full Shade or North Facing Aspects:
60 minutes total run time
Optional Programing: For a Soak and Cycle Watering
Soak and Cycle Sprinkler Time Calculations
Many sprinkler systems are designed to water for shorter durations but activate multiple times throughout the evening. This method, known as deep soaking with multiple cycles, is excellent for allowing water to penetrate the soil more deeply. If your sprinkler system is set up for short bursts through multiple start times, you can calculate the total watering time for each cycle.
South Facing Rotary Heads with 3x Soak Cycles Example:
Soak #1 – 1:00 AM Start Time – 18 minutes run time
Soak #2 – 2:00 AM Start Time – 18 minutes run time
Soak #3 – 3:00 AM Start time – 18 minutes run time
Total Watering Time = 54 Minutes
Total watering time is typically 55 minutes. Divide 55 minutes/ 3 times per night
55 / 3 = 18.3333 minutes per soak cycle (Round down to 18 minutes)
How Many Watering Days Per Week is Based on the Seasonal Temperatures
This is how we got the name 1-2-3-2-1 Watering Technique!
Spring: Water 1 day per week
Early Summer: Water 2 days per week
Summer: Water 3 days per week
Late Summer: Water 2 days per week
Fall: Water 1 day per week
Note: This watering technique was developed by Organo-Lawn.
Approximate Time of Year for When to Add and Subtract Watering Days
Cool and Often Rainy
1 Day Per Week Watering
(Sprinkler Startup through the End of May)
This is an important time for proper lawn watering, as we want to promote deep root growth. If a lawn is overwatered during this period, the roots will remain shallow, which will become a problem when the summer heat arrives.
Water no more than one day per week, when daytime high temperatures average below 70°F. This is generally sufficient from April through the end of May, although this may vary from year to year.
Warm – Not Quite Hot Yet
2 Day Per Week Watering
(Late May – Middle June)
This time of year might be difficult on lawns. The tendency is to water more because the lawn is turning a little brown. Stay patient with 2 day per week watering and the lawn will quickly adjust to the heat.
Water the lawn no more than twice a week, when daytime temperatures tend to be between 70°F and 85°F. This typically occurs from late-May to early or the middle of June. Mondays / Fridays, or Tuesday / Saturday is a good watering schedule.
Hot and Dry
3 Day Per Week Watering
(Middle of June – Middle of August)
This time of year, your lawn may start to develop some brown patches. These areas often indicate poor sprinkler coverage, so you may need to adjust the sprinklers to eliminate these spots. It’s crucial to allow the lawn to go without water for two consecutive days. This will help kill Japanese beetle eggs and prevent damage from grubs later in September.
Water no more than 3 days per week when Colorado’s daytime high temperatures average high temperatures is above 85°F: This is typically is between mid or late June through mid or late August. (I.e. Water Monday/ Wednesday / Friday or Tuesday / Thursday / Saturday)
Cooling Down
2 Day Per Week Watering
(Middle or Late August – Late September)
Reducing water usage is very important this time of year. It starts the process of preparing for winter and it prevents overwatering of the lawn. This is the time of year where overwatering will cause diseases like Necrotic Ring Spot and soil compaction.
Water no more than 2 days per week when daytime high temperatures average between 70°F and 85°F. This is typically between the middle or late August through the middle or late September. (I.e. water Monday / Fridays or Tuesday / Thursday)
Cold Nights & Warm Days
1 Day Per Week Watering
(Late September – Sprinkler Blowout)
To prepare your lawn for the winterization of the sprinkler system, it is important to reduce watering to no more than once a week. This decrease in watering will help prevent winter desiccation and damage from spider mites.
Water no more than 1 day per week when daytime temperatures are 70°F or below. One day per week watering is typically between the middle or late September until the system is winterized for the season.
Instead of the Watering Times – Change the Days per Week!
As temperatures change with the seasons, it’s advisable to adjust the number of watering days rather than extending the duration of each watering session. In the fall, as temperatures begin to cool, it is better to decrease the number of watering days instead of shortening the run time.
Never alter the timing of your sprinkler system zones unless there is a significant change in the amount of sun exposure that a particular zone receives. It’s generally a poor practice to adjust the watering time during the summer.
We aim to water the lawn deeply and allow the soil to dry out between watering sessions. Deep and infrequent watering encourages water penetration to a depth of 10-15 inches, prompting grass roots to grow deeper as the surface soil dries out.
Download a Printable Version of How To Properly Water a Lawn
Do You Need Need Help Setting up Your Sprinklers!
Organo-Lawn can help set up your sprinkler controller to follow the principals of the 1-2-3-2-1 lawn watering technique.
For Sprinkler System Audit Pricing Click on this Link
Quick Summary - 3 Steps to Proper Lawn Watering
Step 1 – Program the controller to water in the early morning hours.
Step 2 – Program each zone based on #1 sun exposure and #2 sprinkler head style.
South – Hot requires longer cycles
East / West – Neither hot nor full shade
North – Cool requires shorter cycles
Step 3 – How many days per week to program the controller
Spring: Water 1 day per week
Early Summer: Water 2 days per week
Summer: Water 3 days per week
Late Summer: Water 2 days per week
Fall: Water 1 day per week
See above for a detailed explanation on how to set this up. Organo-Lawn can also set up your sprinkler system if you order our sprinkler audit service.
Monthly Lawn Watering Schedule for Colorado Lawns
FAQ – How to Properly Water a Lawn
Is it bad to water a lawn at night?
Watering a lawn at night is generally not recommended because it can lead to potential problems for the grass and soil. However, in Colorado our humidity levels are so low that night watering is generally not a major problem. Here are the key reasons why early morning watering is a better option:
- Promotes Fungal Growth
-Grass blades remain wet for an extended period since there is no sunlight and reduced wind to help dry the water.
-This prolonged moisture creates a favorable environment for fungal diseases like brown patch or necrotic ring spot to thrive.
- Encourages Pests
-Wet conditions can attract pests such as slugs and other insects, which can damage the lawn.
- Poor Water Absorption
-While the soil may absorb water more slowly during cooler nighttime temperatures, excess water can lead to oversaturation or pooling, suffocating the grass roots.
- Wasted Water
-Without evaporation to manage water levels, overwatering becomes more likely, leading to water waste and potential lawn damage.
Better Alternatives:
- The best time to water your lawn is in the early morning (2 AM to 8 AM). This allows:
- Ample time for grass blades to dry.
- Optimal water absorption as temperatures are cool, and winds are usually minimal.
- Prevention of fungal diseases.
If watering at night is unavoidable due to water restrictions or other reasons, try to water as early in the evening as possible, so the grass has time to dry before nightfall.
How to water a lawn with a hose and sprinkler head?
Watering a lawn with a hose and sprinkler can be highly effective if done correctly. Here are the steps and techniques to ensure your lawn receives adequate water while minimizing waste and promoting healthy grass growth:
- Choose the Right Sprinkler|
-Oscillating Sprinklers: Best for rectangular or square lawns.
-Rotary Sprinklers: Ideal for circular or irregularly shaped areas.
-Impact Sprinklers: Great for large lawns with high water pressure.
- Determine Watering Needs
-Use a rain gauge or a shallow container (e.g., a tuna can) to measure the water applied.
- Position the Sprinkler Strategically
-Place the sprinkler so that it covers the lawn evenly. Overlap sprinkler patterns slightly to avoid dry patches.
-Adjust the sprinkler’s spray to avoid watering sidewalks, driveways, or roads.
- Water Deeply and Infrequently
-Follow the same principles of the 1-2-3-2-1 lawn watering technique.
- Pro Tip: Use a Timer
-Attach a timer to your hose to ensure consistent and efficient watering, even if you’re not available to monitor the process.
By following these techniques, you can maintain a lush, healthy lawn without an automated sprinkler system.