Do You Need to Winterize Your Sprinkler System in North Texas?

Oct 8

5 min read

Every fall I get some version of the same question. Usually it comes from somebody who moved here from up north, where blowing out the sprinkler lines every October was just part of owning a house. They want to know when I can come do theirs.

The short answer is that most North Texas systems don't need that. But there is one part of your system that does need attention before the first freeze, and if you remember February 2021, you probably remember what happens when it doesn't get it.

The average first freeze at DFW Airport is November 22, and it has come as early as late October. So the next few weeks are the right time to take care of this, not the night the freeze warning goes out.

Why We Don't Blow Out Lines Here

Up north, the ground freezes several feet down and stays frozen for months. Any water left in a buried sprinkler pipe turns to ice and splits it, so the only safe move is to push every drop out with compressed air and leave the system dry until spring.

Our winters don't work like that. Most of our freezes happen overnight, the sun warms things back up the next afternoon, and the ground rarely freezes deep enough to reach the lines buried in your yard. A blowout is extra cost for protection the buried part of your system usually doesn't need.

There's another reason I don't like shutting a North Texas system down for four months. We get plenty of dry winters, and a dormant lawn still has living roots. If we go several weeks without rain, it needs a drink about once a month.

A system that's been drained and closed up for the season can't give it one.

The Part That Actually Breaks

The piece to worry about is your backflow preventer. It's the brass assembly sticking up out of the ground, usually near the house or close to where your water line comes in. Its job is to keep sprinkler water from flowing backward into your drinking water, which is why the state requires one on every system.

The problem is where it sits. It's above ground, it's full of water, and it's built with small chambers and valves that don't leave ice much room to expand. A long, hard freeze can crack the brass body or split the valves, and there's no patching that. It has to be replaced, and the replacement has to be tested before it goes back in service.

After February 2021, most of the replaced backflow preventers belonged to homeowners who had wrapped their outdoor faucets and never thought about the brass fitting a few feet away.

Some homes have a different kind of backflow device buried in a small box in the yard instead. It's less exposed, but it's still worth a look before winter. And if you have more pipe above ground, you have more to protect.

That's common on the acreage lots in Argyle, where long sprinkler runs often mean more pipe and equipment sitting out in the open.

What I Recommend Before the First Freeze

None of this takes long, and most of it you can do yourself in an afternoon. Here's what I'd do, in this order.

1. Cover the backflow preventer.

Get an insulated backflow cover from the hardware store, sized for your device, and make sure it reaches all the way to the ground. Wrap any exposed pipe underneath it with foam pipe insulation first. Old towels and a bucket will work in a pinch, but towels get wet and stop insulating. Put the cover on in November and leave it on until mid-March.

2. Check your freeze sensor.

A lot of systems have a small sensor near the controller or up on the eave that shuts everything off when the temperature drops. Smart controllers can do the same thing off the weather forecast. October is the time to make sure yours actually works. Every system we install comes with a smart controller for this reason, and adding a freeze sensor to an older system is a small job.

3. Switch the controller to off or rain mode before a hard freeze.

Running sprinklers on a freezing morning puts a sheet of ice on your sidewalk, your driveway, and the street out front. That's a real hazard for whoever walks or drives through it, and it doesn't do your grass any favors either.

4. Water a day or two ahead of a hard freeze.

Moist soil holds heat better than dry soil, which gives the roots of your shrubs and bed plants a little more protection. Just don't run it the night of. This matters most for anything planted this fall, since those roots haven't spread out yet. It's one of the things we plan around on fall landscape and planting jobs.

5. For a long, hard freeze, shut off the water and drain the backflow.

A cover is enough for a typical overnight freeze. When the forecast calls for several nights in the teens, or days that never get above freezing, I'd go a step further. Turn off the water supply to the sprinkler system, open the small test valves on the backflow preventer, and leave its two handles halfway open so no water sits trapped inside.

If you don't know where your sprinkler shut-off valve is, find it now. Ten o'clock on the night of a freeze warning is a bad time to start looking. This is also the part a lot of people would rather hand off, and it's what we take care of on a sprinkler winterization visit.

What to Do If Something Breaks Anyway

Freezes don't always follow the forecast, and damage sometimes doesn't show up until the next time the system runs. These are the signs I'd watch for after a hard freeze.

Water spraying or dripping from the backflow preventer once things thaw
A crack or a bulge in the brass body
No water reaching any zone when the system runs
A wet spot near the house that wasn't there before

If you see any of those, turn off the water to the sprinkler system and leave it off until someone takes a look. A cracked backflow preventer is one of the most common sprinkler repair calls we get after a hard freeze.

If just one zone won't come on in the spring, that often isn't freeze damage at all. I wrote about why one sprinkler zone stops working and how I figure out which problem it is.

Want Us to Handle It?

If you'd rather not think about any of this, we'll take care of it. On a fall winterization visit, we check your freeze sensor, protect the backflow preventer, show you where your shut-off valve is, and set your controller for winter. Then we come back in the spring and bring it all back up.

We do this for homeowners in Lewisville, Flower Mound, Highland Village, Lake Dallas, Corinth, and Argyle. Get a quote before the first freeze, or call us at 972-684-3319.