When a hard freeze warning comes across your phone in Houston, most people think about their pipes and their plants, but they skip over the one system that can cost thousands to repair if you get it wrong: your irrigation. A frozen sprinkler line or controller can crack, burst, or short out in ways that take months to fix once the weather warms up. The good news is that preparing your system takes a few hours and some basic steps you can do yourself, or you can call in a professional to handle it before the cold snap hits.
Turn Off Your System Early
The most important thing you can do is shut down your irrigation at least 24 hours before temperatures drop below freezing. Don't wait until the freeze warning goes into effect. Turn off your controller now. If you have an automatic timer, switch it to the "off" position, not just a pause mode. The system needs to sit dormant so that no water is sitting in the lines when the cold hits. Even a small amount of water left in a pipe will expand when it freezes and can split the line from the inside out.
Drain Your Lines Completely
After you turn off the system, you need to get the water out. Most modern irrigation systems in Houston have drain valves at the lowest points of each zone. Walk your yard and locate these valves, usually small brass fittings with a handle or a slot for a flathead screwdriver. Open them all and let the water drain for at least an hour. If you're not sure where your drain valves are, check your system map or call the company that installed it. Some systems have automatic drain valves that release water when pressure drops, but don't count on that in a freeze. Manual draining is more reliable.
If your system has quick couplers or sprinkler heads that sit above ground, you may want to blow out the lines with compressed air. This removes water from the pipes more thoroughly than gravity alone. You can rent an air compressor from a hardware store if you don't have one. Set it to low pressure, around 40 PSI, and work through each zone slowly. High pressure can damage the fittings and heads.
Protect Your Controller and Timer
Your irrigation controller is usually mounted on the side of your house or in a garage. This is an electrical device, and freezing temperatures combined with moisture can damage the wiring and circuit board. If your controller is outside and exposed, wrap it loosely with a blanket or burlap sack. Don't seal it completely, because you want some air circulation to prevent condensation. If you have a cover for it, even a plastic storage box propped over it, that's better than nothing. For controllers mounted in a garage or shed, make sure the space doesn't get below freezing. If it does, you may need to move it or add a small heater.
Insulate Above-Ground Components
Sprinkler heads, valves, and backflow preventers that sit above ground are the most vulnerable to freeze damage. Wrap any exposed valve boxes with foam pipe insulation or old towels secured with duct tape. For backflow preventers, which are required by code in most Houston neighborhoods, wrap the whole assembly. These devices are expensive to replace if they crack. If you have a rain sensor or freeze sensor, those can also be damaged, so check that they're protected too.
Leave Your Faucets Alone
You'll hear advice about leaving outdoor faucets dripping during a freeze. Don't do that to your irrigation system. Your sprinkler lines are designed to be drained and shut off. Leaving water running defeats the whole purpose of shutting down the system. That said, if you have separate outdoor hose bibs that are not part of your irrigation system, those are a different story. Those can benefit from dripping or being drained separately.
When to Call a Professional
If your system is more than ten years old, has zones you're not sure about, or if you've never had it winterized before, this is the time to call someone who knows the system. A professional winterization takes a couple of hours and costs between 150 and 300 dollars depending on the size of your system. That's cheap insurance against a 1500 dollar repair bill in February when a line bursts and you're waiting for a plumber. JB Irrigation & Services can walk through your system, identify all the drain points, blow out the lines, and make sure everything is protected before the freeze hits.
After the Freeze
Once temperatures stay above freezing for a few days and the ground thaws, you can turn your system back on. Do it slowly. Turn on your controller and run through each zone for just a few minutes to make sure water is flowing normally. Look for any leaks or broken heads. If you see water spraying from an unexpected place or a valve box that's wet, that's a sign of freeze damage that needs attention.
JB Irrigation & Services has been helping Houston homeowners protect their systems for years. If you're not confident about winterizing on your own, or if you want a professional to check your system before the next freeze, give us a call. We'll make sure your sprinklers are ready for whatever the Houston winter throws at them.
