Winterizing your drip irrigation system is just as important as winterizing your sprinkler system—maybe more so, because drip tubing and emitters hold water in small spaces where ice damage happens fast. I’ve replaced countless drip lines and fittings for people who skipped the 30-minute winterization process. Here’s my step-by-step guide to protecting your drip system through freezing temperatures.
When Should You Winterize Your Drip System?
Winterize before the first hard freeze—typically when overnight temperatures are forecast to drop below 32°F (0°C) for more than 4 hours. For most of the US, that’s between October and December depending on your zone. In colder regions (zones 5 and below), start the process by mid-October. In milder zones (7-8), late November or early December is usually fine. I check the 10-day forecast and winterize when I see a freeze warning. For broader winterization guidance, my sprinkler system winterization guide covers the full property-wide process.
How Do You Drain Drip Tubing for Winter?
Start by shutting off the water supply at the source. Open the end cap or flush valve on each drip line and let gravity drain the water out—elevate the tubing slightly if needed to help water flow to the low end. For ½-inch drip tubing on a slight slope, gravity drains about 80% of the water. For flat runs, use a compressor or blow-out adapter. Remove and drain the pressure regulator, filter, and any inline valves. Store these components indoors—the rubber diaphragms and gaskets freeze-crack at 20°F. Coil loose tubing and store it in a shed or garage if possible. For in-ground drip lines, blowing them out with air is the safest method. For the blow-out procedure, see my irrigation repair guide.
How to Blow Out Drip Lines with an Air Compressor?
Set your compressor to 30-40 PSI maximum—never exceed 50 PSI on drip tubing or you’ll blow emitters off the line. Use a blow-out adapter ($15-25 at hardware stores) that connects the compressor hose to the drip system’s hose bib. Open the farthest drip line end cap. Turn on the compressor and let air flow through until no more water mist comes out—usually 1-3 minutes per line. Work from the farthest zone back to the nearest. Important: do not run the compressor with the end cap closed—you’ll pressurize the line and burst connections. After blowing out each line, close the end cap loosely to keep debris out. For a complete guide to winterization equipment, check my installation guide.
Drip tape is easiest—just roll it up, shake out any remaining water, and store it in a garage, basement, or shed. Drip tape left in the field over winter degrades 2-3 times faster from UV and freeze-thaw cycles. I replace mine each spring anyway, so storing it is optional. For solid drip tubing, remove and store the following components indoors: pressure regulator ($8-15 replacement if left out), filter screen and bowl ($5-10 replacement), inline valve diaphragms, battery timer (remove batteries), and any brass fittings (they crack in freezing temps). Store them in a bucket with the end caps to keep small parts together. For filter and regulator care, see my pressure regulator guide.
What Happens If You Skip Winterization?
Ice expands by about 9% in volume, which is enough to: crack brass and plastic fittings (replacement cost $2-10 each), split drip tubing along seams (replace entire run—$30-50 for a 200-foot bed), destroy the silicone diaphragm in pressure regulators (new regulator $10-15), pop emitters off their barbs (reinstall or replace—$0.25-0.50 each), and crack filter bodies (replacement $10-20). A full winterization takes 30-60 minutes and costs nothing in materials. Skipping it can cost $50-150 in replacement parts and an entire afternoon of re-installation in spring. For the cost breakdown of annual system maintenance, see my irrigation system cost guide.
References
- Irrigation Association — Winterization Standards for Micro-Irrigation — Industry best practices for draining, blowing out, and storing drip irrigation components in freezing climates.
- University of Missouri Extension: Winterizing the Home Irrigation System — Research-based freeze protection recommendations for residential drip and sprinkler systems.
- EPA WaterSense: Seasonal Irrigation System Care — Official guidelines for end-of-season irrigation system shutdown and freeze protection.