By the second week of October, most Houston lawns are still being watered like it's August. The controller hasn't been touched since June, the clay is holding moisture longer, and the St. Augustine is slowing down for the year. That's how you get brown patch — a fungal disease that shows up as spreading circles of dead-looking turf, and it loves wet, cool nights.
Fall is also when summer damage finally becomes visible. Heads got clipped by mowers, nozzles clogged with sediment, a lateral line cracked when the clay shrank in the drought and shifted the pipe. You didn't notice in July because everything was running long enough to cover the gaps. Run shorter cycles and the dry spots show up fast.
Here's what to do about it, in order.
Cut your run times roughly in half
In peak summer, Houston turf wants about an inch to an inch and a half of water a week, counting rain. From October through the end of the year, half an inch to three-quarters is plenty. Cooler nights, shorter days, and lower evaporation mean the soil holds what you give it.
Don't change the frequency first. Change the duration. Two deep soakings a week beat four shallow ones, because shallow watering keeps roots in the top two inches of soil where they cook the following summer. Root depth is the whole game with St. Augustine.
The practical version: if a spray zone was running 15 minutes, drop it to 8. If a rotor zone was running 35, drop it to 18. Then watch for a week. This is DIY, and it takes ten minutes at the controller.
Run every zone manually and watch it
Stand outside and cycle through the system one zone at a time. It takes twenty minutes for a typical eight-zone yard. Look for these things:
- Heads that don't pop up. Usually debris in the riser or a head that got buried under a season of grass growth. Both are fixable in a few minutes with a screwdriver and a trowel.
- Misting instead of spraying. A fine fog means pressure is too high for the nozzle. You're losing water to the wind and starving the far end of the zone. Pressure-regulated bodies solve it.
- Spray hitting the fence, the driveway, or the house. Arcs drift out of adjustment when heads get bumped. Free to fix, and it's usually a quarter turn.
- A wet, spongy patch that never dries. That's a leak in the lateral line or a valve that isn't closing all the way. It won't heal on its own, and it'll show up on your water bill.
- Heads leaning or sunk below grade. Houston clay moves. It swells when it's wet and shrinks when it's dry, and over a few seasons that motion tilts heads and pulls fittings apart.
- Sprays firing into flower beds that don't need them. Turf and beds have different water needs. If they're sharing a zone, the beds are getting overwatered every cycle.
The visual walk-through is DIY. Nozzle swaps and arc adjustments are DIY. Digging up a suspected lateral break is not — you'll be guessing at pipe depth around wire and existing lines.
Check the rain sensor and the backflow preventer
Rain sensors fail quietly. The little disc inside dries out and hardens after a few years of Gulf Coast humidity and sun, and once it stops swelling the system waters right through a thunderstorm. Test it by holding it under water or pressing the plunger while a zone runs. If the zone doesn't shut off, the sensor's done. A replacement typically runs $40 to $120 installed.
Backflow preventers are different. That's the assembly near your meter that keeps irrigation water from siphoning back into your drinking water. Testing and repairing it is regulated work in Texas, and it needs a licensed irrigator. Don't take that one on yourself.
What repairs actually cost
Answering the question most people are actually asking: irrigation repair in the Houston area typically lands between $85 and $250 for a service call covering nozzle replacement, head resets, and adjustments. A failed solenoid or valve replacement usually runs $125 to $300. Lateral line breaks depend on access and depth — figure $150 to $500 once someone has to trench under sod or around a patio.
Full controller replacement, including a smart controller that adjusts to local weather data, generally falls between $250 and $600. Adding a zone to cover a new bed or an area of thin turf tends to run $450 to $900 depending on how far it sits from the existing manifold. Get a local quote — access, soil, and how the original system was laid out move these numbers more than anything else.
Watering after a big rain, and the drainage question
Houston clay drains slowly. After three inches of rain, the top of the soil looks dry the next afternoon while six inches down it's still saturated. Watering on top of that is how you drown roots and feed fungus. Give it three to four days.
If part of your yard stays wet a week after a storm, that's not an irrigation problem. That's grading and downspout routing, and no amount of controller tuning fixes it. Water needs somewhere to go before anything else in the landscape works. Standing water kills more turf here than neglect ever has.
If you do one thing
Cut your run times. Today. It costs nothing, takes ten minutes, and it's the single change that prevents the most damage between now and spring. Everything else on this list can wait a couple of weeks. Overwatering cool, wet October turf can't.