September in Minnesota has a funny way of making winter feel both very far away and much closer than we’d like to admit. The afternoons can still feel like summer, lawns are still green, and irrigation systems may still be running. Then suddenly the overnight temperatures begin dropping, leaves start changing, and everyone remembers there are about a dozen outdoor projects that need to happen before freezing weather arrives.
Your irrigation system should be on that list.
Sprinkler blow out season is approaching, and getting your irrigation system on the schedule before Minnesota temperatures take a serious turn is one of the most important pieces of fall irrigation maintenance. While shutting off the controller ends your watering schedule, it doesn’t necessarily remove the water that remains inside irrigation lines, valves, backflow components, pumps, and other parts of the system.
That’s what a sprinkler blow out is designed to address.
At West Irrigation Services, winterization is considered a required seasonal service for irrigation systems. The goal is straightforward: remove the water that could otherwise remain in the system when freezing temperatures arrive and properly prepare the system for its winter shutdown.
The tricky part isn’t understanding why Minnesota irrigation systems need to be winterized.
It’s knowing when to get it done.
Welcome to Sprinkler Blow Out Season
There isn’t one magical calendar date when every irrigation system in Minnesota needs to be shut down.
Fall weather simply isn’t that cooperative.
September can bring stretches of warm, dry weather when landscapes may still need supplemental water. October can occasionally surprise us with beautiful afternoons. But nighttime temperatures can change quickly, and waiting until freezing weather is already in the forecast can leave homeowners scrambling to find an available appointment.
That’s why it’s better to think in terms of sprinkler blow out season rather than waiting for a specific date.
As the active watering season begins winding down and cooler temperatures become more consistent, homeowners should start planning their irrigation winterization. Getting on the schedule early doesn’t necessarily mean you need to stop watering the second September arrives. It means you have a plan in place before everyone else sees the same cold forecast and starts calling at once.
West Irrigation offers professional sprinkler winterization and blowout services throughout Lake Minnetonka and surrounding communities. Their winterization service is specifically designed to purge water from irrigation systems before freezing conditions arrive.
Insert Internal Link on: “sprinkler winterization and blowout services” → https://westirrigation.com/what-we-do/sprinkler-winterization/
The best time to think about your sprinkler blow out isn’t after the first hard freeze.
It’s while fall still feels comfortable enough that winter isn’t occupying every homeowner’s to-do list.
What Actually Happens During a Sprinkler Blow Out?
You’ve probably heard the term dozens of times, but what does “blowing out” an irrigation system actually mean?
A professional sprinkler blow out uses compressed air to purge water from the irrigation system. Rather than simply shutting off the water source and assuming the system is empty, air is moved through the irrigation zones to help clear water that remains inside the lines.
West Irrigation’s winterization process begins at the backflow preventer, system blow-out point, or lake pump, depending on the system. Air is blown through the irrigation system to empty it of water, and the process also includes draining the backflow or pump and removing pump intakes when applicable.
That last part is particularly important around the Lake Minnetonka area because not every irrigation system is connected to the same type of water source. West Irrigation specializes in both lake pump and well irrigation systems, so winterization may involve more than working through standard lawn sprinkler zones.
Here’s a simple look at what the fall shutdown process may involve:
| Part of the System | What Happens During Winterization | Why It Matters |
| Water supply | Irrigation water source is properly shut down | Stops additional water from entering the system |
| Irrigation zones | Compressed air is used to clear water from the system | Helps remove water before freezing temperatures |
| Backflow components | Drained as part of the winterization process | Helps prepare exposed system components for winter |
| Lake/well pump equipment | Addressed according to the individual system | Pump-fed systems can require additional seasonal steps |
| Pump intakes | Removed when applicable | Helps properly prepare lake pump systems for winter |
| Controller | Prepared for the off-season | Ends the active watering schedule until spring |
The exact process depends on the irrigation system installed at the property, which is one reason professional winterization isn’t simply a matter of hooking up an air compressor and hoping for the best.
Why Can’t You Just Shut Off the Water?
This is probably one of the biggest misconceptions surrounding fall irrigation maintenance.
If no more water is entering the sprinkler system, shouldn’t that be enough?
Not necessarily.
Water can remain inside irrigation lines and system components after the main supply has been shut off. When temperatures fall below freezing, that remaining water can freeze and expand. Pipes, fittings, valves, sprinkler heads, backflow components, and other parts of the irrigation system weren’t designed to act as storage containers for expanding ice.
And because much of an irrigation system is underground, freeze-related problems aren’t always immediately visible.
You may not know something was damaged until spring startup, when the system is charged again and a leak, damaged component, or poorly operating zone suddenly appears.
The basic science behind the concern is simple: water expands as it freezes. The U.S. Geological Survey explains how the expansion of freezing water can exert enough pressure to contribute to cracking and breakage in surrounding materials.
Insert External Link on: “U.S. Geological Survey” → https://www.usgs.gov/special-topics/water-science-school/science/water-density
For Minnesota homeowners, that makes removing water from an irrigation system before prolonged freezing temperatures an important part of preparing the property for winter.
A Sprinkler Blow Out Isn’t the Place to Experiment With an Air Compressor
Owning an air compressor doesn’t automatically make sprinkler winterization a DIY project.
Compressed air needs to be used appropriately for the irrigation system. Different systems can have different layouts, zones, components, pumps, backflow equipment, and winterization points. Improper pressure or airflow can potentially damage system components, while an incomplete blowout may leave water behind.
Then there are lake and well systems.
West Irrigation has specialized experience with lake pump, well, and landscape irrigation systems throughout the western Twin Cities metro. Depending on the property, winterization can involve pump operation, pump drainage, backflow equipment, and intake removal in addition to clearing the irrigation zones themselves.
Professional winterization means the technician isn’t simply making water spray out of each sprinkler head until everything looks dry.
They’re preparing the irrigation system as a whole for months of freezing conditions.
That’s a pretty important distinction.
Your Fall Blow Out Can Tell You Something About Next Spring
Sprinkler blow out season also marks the end of another full year of irrigation use, which makes it a good time to think about how the system performed.
Did one zone seem unusually dry all summer?
Did a sprinkler head stop rotating correctly?
Was there an area that always seemed too wet?
Did your lake pump behave differently toward the end of the season?
Were there leaks, pressure problems, controller issues, or sprinkler heads that were damaged by mowing or landscaping?
You don’t necessarily need to solve every unrelated irrigation issue during the blowout appointment, but don’t forget about the problems you noticed during summer.
West Irrigation recommends routine System Performance Inspections throughout the irrigation season to check system operation and coverage, rain or weather sensors, pump operation when applicable, and controller programming. Those inspections help identify issues that can otherwise go unnoticed while the system continues running.
Their broader residential irrigation services include spring startup, seasonal System Performance Inspections, troubleshooting, repairs, and winterization.
Insert Internal Link on: “residential irrigation services” → https://westirrigation.com/what-we-do/residential-irrigation-services/
Keeping track of concerns at the end of the season can make spring startup considerably easier because you won’t be trying to remember that one sprinkler head you meant to have looked at six months earlier.
Don’t Let a Warm September Fool You
One of the easiest reasons to procrastinate on scheduling a sprinkler blow out is that your irrigation system may still be useful.
That’s completely understandable.
September doesn’t mean your landscape instantly stops needing water. Weather conditions should still guide irrigation decisions as lawns, trees, and landscape plants move toward dormancy.
But scheduling your sprinkler blow out and immediately shutting your irrigation system down are two different things.
The important part is getting ahead of the seasonal rush.
Once the forecast starts showing genuinely cold overnight temperatures, thousands of Minnesota homeowners begin thinking about the exact same fall maintenance projects. Irrigation companies have a finite number of appointments available before winter arrives.
Planning ahead gives you more flexibility instead of turning winterization into a last-minute race against the thermometer.
And Minnesota has a habit of making that thermometer drop rather quickly.
Lake Pump Systems Need Their Own Fall Attention
For homeowners around Lake Minnetonka, there’s another reason sprinkler winterization deserves professional attention.
Many properties rely on lake-fed irrigation systems rather than municipal water. These systems use pumps and intake equipment that introduce additional components into the winterization process.
West Irrigation has spent decades working specifically with lake pump, well, and landscape irrigation systems in the Lake Minnetonka area. During winterization, its service can include draining the pump and removing pump intakes where applicable in addition to clearing water from the irrigation system.
That system-specific knowledge matters.
A standard residential irrigation system and a lake-fed system may ultimately share the same winter goal—remove water and prepare equipment for freezing temperatures—but how you get there isn’t necessarily identical.
This is one of those areas where local experience is particularly valuable. Minnesota winters aren’t theoretical to an irrigation company that’s been working through them since 1989.
Sprinkler Blow Out and Spring Startup Are Two Halves of the Same Cycle
It can be helpful to think of irrigation maintenance as a yearly loop rather than a collection of unrelated appointments.
Spring startup prepares the system for another watering season. System Performance Inspections help maintain proper operation as weather and landscape needs change. Fall winterization closes the system down and prepares it for freezing conditions.
Then spring arrives and the cycle begins again.
A system that has been properly winterized still needs to be brought back online thoughtfully. At startup, the water supply can be restored, zones can be inspected, sprinkler coverage can be evaluated, pumps can be checked where applicable, and controller programming can be adjusted for spring conditions.
Winterization isn’t meant to guarantee that no component will ever need maintenance again.
It’s about giving the irrigation system the proper seasonal shutdown it needs before spending months in a Minnesota winter.
Get Ahead of Sprinkler Blow Out Season
Nobody wants to think about winter while they’re still enjoying warm September afternoons.
Unfortunately, Minnesota doesn’t usually wait for us to feel emotionally prepared for freezing weather.
Sprinkler blow out season is the reminder that irrigation systems need their own fall preparation before the temperatures stay below freezing. Shutting off your controller isn’t enough if water remains inside the system, and waiting until freezing weather is already here can make scheduling much more stressful than it needs to be.
West Irrigation Services has been working with residential and commercial irrigation systems in the western Twin Cities metro since 1989, with specialized experience in lake pump, well, and landscape irrigation systems.
If your sprinkler system still needs its fall blow out, now is the time to start thinking about the schedule—not the night the first hard freeze appears in the forecast.
Finish watering for the season.
Get the system properly winterized.
Then let Minnesota do what Minnesota does.
Your sprinklers can sleep through this part.