Fall Irrigation Shutdown for Central Ohio

If you have an in-ground irrigation system in Central Ohio, the fall shutdown is one of those jobs that has to happen at the right time or you end up with cracked pipes, blown fittings, and a repair bill in April that costs more than ten years of properly scheduled blowouts. I’ve been working lawns across Pickaway, Franklin, Fairfield, Ross, and Fayette counties for more than ten years, and the irrigation shutdown question comes up every year right around now. This is what I tell my own clients, what the timing actually looks like, and what to ask if you’re hiring out the work.

When should I shut down my irrigation system in Central Ohio?

Mid-October through early November for most Central Ohio properties, with the absolute latest reasonable date being the week of Thanksgiving. The earliest reasonable date is mid-October, and only if you are not actively watering an overseeded lawn or a newly planted ornamental bed.

The decision is driven by two things working against each other. On one side, freezing temperatures will damage water left in the lines, valves, and backflow preventer. On the other side, the lawn and landscape may still need irrigation through October if the weather turns warm and dry. Per OSU Extension’s turfgrass irrigation guidance, cool-season lawns can need supplemental water as late as the third week of October in dry years.

My rule on most Central Ohio properties: blow out the system the week of October 20 if there is no overseed in play and the forecast shows nighttime lows trending into the 30s. Push the blowout to November 1 if the property was overseeded and germination is still completing. Never go past November 15 unless you have a specific reason — by then, hard freeze nights are reliable and the line damage risk is real.

On a Canal Winchester property I service that’s on an overseed schedule, we are holding the blowout until October 28 this year. The seed went down September 21, germination is at about 70 percent, and the lawn still needs another week of light irrigation to finish. On a Bexley client without overseed, we blew that system out yesterday because the bed plants are established and the lawn is at adequate moisture from this week’s rain.

What does a proper irrigation blowout look like?

Five steps, done in this order.

Step one: shut off the water supply. That means closing the main valve that feeds the irrigation system at the basement or crawlspace tap. If you can’t find your shutoff or you’ve never used it, this is the moment to identify it and make sure it actually works. Stuck shutoff valves are a common surprise on October blowouts.

Step two: relieve the pressure. Open a hose bib downstream of the shutoff or activate a manual drain valve if your system has one. This drops the line pressure to zero before air goes in.

Step three: connect the compressor. A real blowout requires a commercial air compressor — typically 80 to 185 CFM at 50 to 80 PSI. A pancake compressor from the garage is not enough. There is not enough volume to push water out of long lateral runs and head bodies, which means water sits in the system anyway and freezes in place.

Step four: blow each zone in sequence. Activate each zone individually at the controller, let the compressor push air through until the heads sputter and run dry, then move to the next zone. Each zone gets two to three passes. Do not run a single zone for more than 90 seconds at a time — pressurized air without water cooling the heads will damage the seals.

Step five: drain the backflow preventer. This is the part most homeowners miss when they try to DIY. The backflow preventer above ground has internal chambers that will hold water and crack with the first hard freeze. Open the test cocks, drain the body, and leave the test cocks at a 45-degree angle for winter.

If any of that sounds like more than you want to handle with rented equipment, the call to a professional is usually $75 to $150 for a residential blowout. That’s less than the cost of one cracked PVC fitting under your patio.

What happens if I skip the blowout?

You roll dice on cold weather damage. In a mild winter you might get away with it. In a normal Central Ohio winter, you’ll see one or more of these problems by spring.

Cracked PVC laterals. Water left in lateral lines expands when it freezes and splits the pipe. You won’t know until you turn the system on in April and water boils up out of the lawn. Repair requires digging up the line, splicing the break, and re-sodding the dig site.

Broken head bodies. Pop-up sprinkler head bodies fill with water through the lateral, and frozen water cracks the housing. Each broken head is $25 to $60 in parts plus labor. On a system with 40 heads, that adds up.

Damaged backflow preventer. The most expensive failure point. A cracked backflow body is a $400 to $900 replacement including the plumbing work and the new device. They’re not optional — Ohio code requires a working backflow on any irrigation system tied into the potable water supply.

Failed valves. Solenoid valves in the manifold can crack if water sits in them through a freeze. Each valve replacement is $80 to $200.

On a Lancaster client property the spring after a skipped blowout, we found three cracked laterals, eleven broken pop-up bodies, and a destroyed backflow. The total repair was over $2,800. The blowout that would have prevented it was $135.

How does the irrigation shutdown interact with my overseed and fall lawn work?

This is the timing question most homeowners get wrong. They’ve heard “shut down irrigation in October” and they do it in early October, then their overseeded lawn dries out and germination fails.

If you overseeded in mid to late September, your lawn needs consistent moisture for 14 to 21 days for germination to complete and for the first six weeks to establish a root system. That means you probably need irrigation through at least the third week of October — possibly later if the weather is dry.

My sequence on overseeded lawns:

• Overseed in last week of September
• Light, frequent irrigation through germination (typically October 1-15)
• Taper to deep, infrequent watering once germination is complete (October 15-25)
• Final watering pass around October 28 to make sure the new turf goes into winter with adequate moisture
• Blow out the system the first week of November

On a non-overseeded lawn, the timing can move two weeks earlier without consequence. If you’re trying to coordinate aeration, overseed, fall feed, mowing, leaves, and irrigation shutdown at the same time, our aeration and overseed service bundles the lawn work and we coordinate timing with your irrigation contractor.

What about hose bibs, outdoor faucets, and rain barrels?

Same logic, different scope. Anything outside that holds water and connects to your plumbing needs to be addressed before the first hard freeze.

Hose bibs and outdoor spigots. Disconnect garden hoses by mid-October. A hose left attached to a spigot can hold water back into the wall pipe and freeze it. If you have frost-proof spigots, disconnecting the hose is usually sufficient. If you have standard non-frost-proof spigots, also shut off the interior valve and bleed the line.

Rain barrels. Drain by the first hard freeze, typically late October to early November in Central Ohio. Flip the barrel over or move it indoors. A full rain barrel left out through winter will crack from ice expansion.

Drip irrigation lines. Drip systems need a different blowout pressure than spray systems — typically 25 to 40 PSI rather than 50 to 80 PSI. If you have drip zones, mention that to whoever is blowing out the system. Standard sprinkler pressure can blow drip emitters off the line.

Outdoor decorative fountains. Drain the basin and the pump, disconnect electrical, and cover for winter. Fountains left out with standing water will crack the basin and destroy the pump.

What about commercial properties and irrigation contracts?

Commercial properties usually have their irrigation on a separate maintenance contract from the lawn service. Make sure those two contractors are talking to each other. The lawn service knows what’s been overseeded and what’s been treated. The irrigation contractor knows the system layout and the blowout sequence. If they’re not coordinated, you get a shutdown that happens too early on a freshly overseeded lawn or too late on a system that already had a freeze night.

For our HOA and commercial clients, we coordinate directly with the irrigation contractor. Our commercial landscape services include that scheduling overhead because it’s the kind of detail that gets missed when nobody owns it.

Quick fall irrigation shutdown checklist

• Plan blowout for the week of October 20-November 5 for most properties
• Push to November 1-10 if the lawn was overseeded
• Use a 80-185 CFM commercial compressor, not a pancake
• Blow each zone two to three passes, 90 seconds maximum per pass
• Drain the backflow preventer and leave test cocks at 45 degrees
• Disconnect hose bibs by mid-October
• Drain rain barrels and decorative fountains before first hard freeze
• Coordinate with overseed and aeration schedule
• Coordinate with any other fall property work

Want a written quote?

If you’d rather not coordinate irrigation timing with overseed, aeration, leaves, and the rest of fall lawn work yourself, Lawn Harmony Landscaping handles full-service lawn care across Central Ohio and coordinates with your irrigation contractor on shutdown timing. We’re locally owned and operated, licensed and insured, with a 5.0-star Google rating and more than ten years on these lawns.

Get a free quote, call (614) 425-9789, or email LawnHarmonyOhio@gmail.com. Commercial properties can request a walkthrough at /quote/commercial.

Service area: Columbus, Bexley, Grandview Heights, Upper Arlington, Grove City, Pickerington, Canal Winchester, Groveport, Circleville, Ashville, Lancaster, Baltimore, Chillicothe, Washington Court House, and Jeffersonville.