Freezing weather can destroy your sprinkler system — here's how to winterize it now

1. Turn off the water to your sprinklers

Find the valve that controls water going to your sprinkler system. It's usually in a green box somewhere in your yard, often near your water meter. Open the box and look for the valve — you want to turn it so it's sideways (perpendicular) to the pipe. That's the "off" position.

Make sure you're shutting off just the sprinklers, not the water to your whole house. If you're not sure which valve is which, check any paperwork from when the system was installed, or call the company that put it in. This first step stops new water from entering the system so you can drain what's already there.

2. Let the water drain out

Now you need to open the drain valves so trapped water can escape. These valves are scattered around your system, usually at the lowest spots where water naturally flows. You'll find them in small boxes buried in your yard.

Open each one by turning it counterclockwise. Water will start flowing out. This releases the pressure in your system and starts getting rid of the standing water. Leave these valves open all winter — that way if any water gets in, it can drain out instead of freezing inside your pipes.

3. Empty the backflow preventer

The backflow preventer is that device above ground near where your sprinkler system connects to your house water supply. It has two valves attached to it and two small drain screws on the sides. This part is expensive to replace, so you really don't want it to freeze and crack.

Turn both valves to a 45-degree angle (halfway between on and off). Then use a screwdriver to open those two small drain screws on the side of the device. Water will drip out. Make sure it's completely empty before winter hits.

Some sprinkler systems have automatic drains built in that open by themselves when the water pressure drops. If yours has these, they should have already started draining when you shut off the water. Give it 30 minutes to an hour and check the valve boxes to see if water has drained out.

If your system has manual drains instead, you need to open the valves at the lowest points yourself to let gravity pull the water out. Walk around and open any low-point drain valves you can find.

4. Blow out the remaining water with an air compressor

Draining gets most of the water out, but some always stays trapped in the pipes and sprinkler heads. To get rid of this last bit, you need an air compressor. Hook it up to one of the drain ports on your system (you may need a special adapter fitting).

Set the pressure — usually 50 PSI for the hard PVC pipes most systems use, or 30 PSI if you have flexible black polyethylene pipes. Don't go higher than this or you can damage things. Turn on the compressor and then activate one sprinkler zone from your control box.

You'll see water spray from the heads, then it'll turn misty, then just air will come out. Once you only see air, move to the next zone. Do this for every zone in your system.

5. Do a final check before it freezes

After everything's drained, walk around and make sure you've covered all the bases. Leave all those drain valves open so water can escape if any gets in. Double-check that the backflow preventer is bone dry.

If it sits above ground, wrap it in foam insulation or buy a cover for it. If you have a portable sprinkler timer, bring it inside.

If it's permanently mounted outside, just turn it to "off" or "rain mode." After the first freeze, go check everything one more time to make sure nothing cracked. Doing all this now saves you from expensive surprises in spring.