Planning guide
When to winterize sprinklers in the DC area
Many DC-area homeowners schedule their sprinkler blowout in the fall, before the first hard freeze. Water left in the lines can freeze, expand and crack pipes, valves and heads.
Timing tips
- Watch the forecast for the first hard freeze and book ahead of it
- Fall is the busiest season, so request early
- Areas farther from the city, like Loudoun and upper Montgomery County, can get colder sooner
Before the crew arrives
- Know where your irrigation shut-off and backflow preventer are
- Make sure the controller is accessible
- Flag any zones that weren't working this season so they can be noted for spring
If you missed it
If a freeze arrives before your blowout, contact an irrigation company; they can advise on next steps and check for damage in spring.
Signs freeze damage happened
- Water bubbling up in the yard at spring start-up
- Cracked heads or a split backflow device
- Zones with low pressure
- A spike in the water bill after turning the system on
Typical fall timing by area
| Area | Often |
|---|---|
| DC and inner suburbs | Later in fall |
| Fairfax, Montgomery County | Mid to late fall |
| Loudoun, upper Montgomery, Frederick edges | Earlier, as they cool sooner |
Watch local forecasts; these are general patterns, not dates.
Booking tips
Request your blowout early in the fall; many companies open booking weeks ahead and fill their schedules before the first freeze. If you're traveling, ask whether the company can do the blowout while you're away, as long as they can reach the shut-off and controller.
Questions
Is a blowout really necessary?
Many irrigation companies recommend it in freezing climates. Ask a local company about your system.
What if I have a drip system?
Drip zones need winterizing too. Mention them in your request.
Can I water in late fall before the blowout?
New plantings may need water. Ask the company to schedule the blowout around it.
Sprinklers acting up?
Send the details once and hear back from local irrigation companies.