Smart Irrigation Controllers: Are They Worth It in Montana?

What is a smart irrigation controller?

EPA WaterSense recognizes two kinds. Weather-based irrigation controllers use local weather data and landscape conditions to set the amount, frequency and timing of watering. Soil moisture-based controllers measure moisture in the ground under the landscape and override scheduled irrigation when plants do not need water. EPA says both come as stand-alone controllers or as add-on devices that work with an existing clock-based controller.

The contrast is with the standard clock timer, which runs whatever it was set to in May until someone changes it. EPA estimates that more than 28 million U.S. homes have in-ground sprinkler systems, typically run by clock-based controllers, and its Sprinkler Spruce-Up page says homes with clock timer controlled systems use about 50 percent more water outdoors than homes without irrigation systems.

How much water do they actually save?

EPA's figures for WaterSense labeled products: replacing a standard clock-based controller with a labeled weather-based controller can save an average home nearly 7,600 gallons of water a year, and installing a labeled soil moisture-based controller can save an average home with an automatic system more than 15,000 gallons a year. Those are national averages. A Missoula lawn on city water and a Bitterroot acreage on a well will see different numbers, but the direction is consistent: the savings come from the days and weeks a clock timer would have watered when the landscape did not need it.

What does the WaterSense label mean?

It means the product was independently certified against EPA criteria, not just marketed as smart. For weather-based controllers, EPA tests irrigation adequacy (meeting the plants' needs), irrigation excess (avoiding overwatering) and supplemental capability, such as accommodating watering restrictions; the test method is adopted into ANSI/ASABE S627, and specification version 1.1 dates to September 2021. For soil moisture controllers, EPA certifies function, precision, response to changes in soil moisture, function after freeze conditions and supplemental capabilities, under ANSI/ASABE S633, with the specification released February 11, 2021. The freeze test matters in Montana.

Why do they fit Montana's watering season so well?

Because our season changes fast at both ends. A schedule set for July is far too much in May and September, and a clock timer left alone through a wet June or a cool September wastes water and keeps roots shallow. Montana State University Extension's Yard and Garden Water Management MontGuide advises not watering when it is going to rain, has just rained or is raining, avoiding windy periods, and installing a rain sensor so the system does not have to be shut off by hand. A weather-based controller automates exactly those adjustments.

If you are on Missoula Water, a controller also makes it easy to keep runs inside the city's recommended watering hours, which we cover in outdoor watering in Missoula.

Weather-based or soil moisture: which is better?

They answer different questions. A weather-based controller estimates how much water the landscape used from weather data, which works well across a property with uniform zones and few microclimates. A soil moisture controller measures directly, which can be more precise but depends on the sensor being placed in a spot that represents the zone. On lots with deep shade on one side of the house and full sun and wind on the other, either type needs zones that are already split by exposure; a controller cannot average a sunny slope and a shady bed into one sensible schedule.

For most residential systems we install a weather-based controller and set each zone's plant type, soil, sun and head type properly. For properties where a single sensor location can represent a large uniform area, a soil moisture add-on is worth discussing.

What can a smart controller not fix?

Anything mechanical or anything in the layout. EPA's Sprinkler Spruce-Up starts with inspecting for heads that do not pop up fully, tilted heads, broken heads, leaking joints and valves that do not close fully, and then directing heads for head-to-head coverage. None of that is the controller's job. If a zone has a dry arc because two heads do not reach each other, a smarter schedule will simply run longer and overwater the rest.

The same is true of zone design. Colorado State University Extension advises not mixing sprinkler types in a zone because each delivers water at a different rate. A zone that mixes sprays and rotors has no correct run time, smart or not. That is why we check a system before recommending a controller, using the same approach described in our guides to irrigation leak signs, sprinkler head types and zone design.

Do they need Wi-Fi, and what about winter?

Most weather-based controllers use an internet connection to pull weather data, so the controller location needs a reliable signal or a wired connection; some add-on devices use an on-site sensor instead. In winter, Colorado State University Extension advises keeping the irrigation controller powered so transformer heat helps reduce moisture, and running it through a minimum cycle once a week to keep the solenoid plungers from sticking, after the system has been blown out. Set the controller to its off or rain mode when the system is winterized; it should never try to run a dry, blown-out system for real.

Are there rebates in Missoula or the Bitterroot?

We did not find a current smart controller rebate from the City of Missoula when we checked in November 2026, and we do not want to promise one that does not exist. EPA notes that some utilities offer rebates for WaterSense labeled outdoor products and maintains a rebate finder on its Look for WaterSense site. Ask your water provider, and check again in spring, because programs change.

So is a smart controller worth it?

It is worth it when the system underneath is sound: heads working, zones split by plant type and exposure, and no leaks. In that case a controller is one of the easiest efficiency gains available, and EPA's savings figures show why. It is not worth it as a substitute for repairs or redesign; fix those first. If you water from a well, the controller also helps you stay inside what the well can deliver, which our well water irrigation guide explains.

Pairing a controller with metered water is useful too. Missoula Water says its AMI meters transmit readings every 15 minutes and let customers set up alerts for continuous flow, which often indicates a leak. A controller that waters on schedule and a meter that flags anything unusual make a good team.

Which settings matter most once it is installed?

A smart controller is only as good as what it is told about each zone. The settings that make the biggest difference are the plant type (lawn, shrubs, trees, drip beds), the soil, the slope, the sun exposure and the head type, because together they determine how fast water goes on and how fast the soil can take it. Get the head type wrong and the controller's math is wrong from the first run.

Slopes and slow soils need cycle-and-soak. EPA's Sprinkler Spruce-Up recommends splitting irrigation into shorter intervals with breaks in between if runoff occurs, which lets water soak in and promotes deeper roots, and EPA's watering tips say the same approach helps on clay soils and slopes. Most smart controllers can do this automatically once the slope and soil are entered. MSU's MontGuide offers a simple field check that works with any controller: push a quarter-inch or three-eighths-inch metal rod into the soil after watering, and where it stops is how deep the water went.

How does HJ handle controller upgrades?

We check the system first, repair what needs it, and then install and program the controller zone by zone so the settings reflect what is actually planted. Controller and rain sensor faults are part of our sprinkler repair work, and new systems are covered on our irrigation systems page. This guide is part of our Montana Landscaping, Lawn & Irrigation Guide. Call HJ Property Care & Tree Service at (406) 215-7319 or request a free estimate. We work across Missoula and Ravalli counties, from Missoula and Lolo to Florence, Stevensville, Corvallis, Victor, Hamilton and Darby.

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