How to Build a Sprinkler Watering Schedule for North Texas (and Program It Into Your Controller)

What you'll learn:

• The three questions every watering schedule has to answer
• Why identical runtimes on every zone are always wrong
• The tuna can test, and why it matters most on older, reworked systems
• The runtimes I actually program on DFW systems
• Why clay soil forces you to split runtimes into cycles
• The start-time mistake I find on half the controllers I open

Experience level: Beginner (a notepad, a few tuna cans, and 30 minutes at the clock)

A Watering Schedule Is Three Answers

Most controllers I open in North Texas are running a schedule somebody invented in thirty seconds: every zone 10 minutes, three days a week, whatever time the installer happened to set. That schedule overwaters the shady spray zones, underwaters the rotor zones, and runs off the clay before it soaks in.

A real schedule answers three questions, zone by zone:

1. How much? How many minutes does this zone need to put down the water the grass actually uses?
2. How often? How many days a week, and how does that change through the seasons?
3. When? What time of day does the water do the most good?

Answer those three and programming the clock at the end is the easy part. Skip them and no amount of button-pushing will save the schedule.

Know What Each Zone Puts Down

The single biggest scheduling mistake is treating all zones the same. Different head types deliver water at wildly different rates. The book numbers look like this:

Zone type	Published precipitation rate
Fixed spray heads	~1.5 in/hr
Rotors (rotating streams)	~0.5–0.75 in/hr
MP rotators / multi-stream	~0.4 in/hr
Drip (beds and foundations)	measured in gallons/hr, not inches

That table is why "10 minutes on every zone" fails. Ten minutes on a spray zone is a real drink. Ten minutes on an MP rotator zone is barely a heavy dew. If your controller runs identical times on mixed zone types, some part of your yard is losing.

Treat the book numbers as a starting point, not gospel. What your zones actually put down depends on pressure, nozzle sizes, head spacing, and how many times the system has been reworked, which is why the runtimes I program (below) do not fall straight out of that table.

Walk your system once and write down what each zone is: spray, rotor, rotator, or drip. If a single zone mixes sprays and rotors, that zone can never be scheduled correctly, and it is worth reading my guide on why mixed zones fail.

The Tuna Can Test: Measure, Don't Guess

The published rates assume heads laid out on a neat grid with matched nozzles. A lot of DFW systems have not looked like that in years. The systems where I most want a real measurement are the older ones that have been reworked over and over: a head added here after a patio went in, a zone extended there, spacing that is not a grid or even a straight line. On a system like that, the book number tells you almost nothing. Measuring does.

Professionals measure precipitation with calibrated catch cans placed across a zone. You can get a usable number with tuna cans:

1. Set out six or more straight-sided cans spread across one zone: near heads, between heads, at the edges.
2. Run that zone for 15 minutes.
3. Measure the depth of water in each can with a ruler and average them.
4. Multiply by four. That is your zone's real precipitation rate in inches per hour.

The spread between cans tells you something too. If one can caught a half inch and another caught almost nothing, the zone has a coverage problem no schedule can fix, usually a tilted head, a clogged nozzle, or spacing that got scrambled during one of those reworks. Fix coverage first; a schedule can only distribute the water your heads deliver.

How Long to Run Each Zone

North Texas turf wants about an inch of water a week during the growing season, counting rainfall. Here is where I land on real systems, and you can find the full season-by-season breakdown in my DFW seasonal watering schedule:

• Spray zones: about 28 minutes per week in peak summer, split across the two allowed watering days, so about 14 minutes per watering day.
• Rotor zones: roughly double the spray runtime. Call it 55 to 60 minutes a week.
• Rotator zones: longer still. If you converted heads to MP rotators to save water, the savings come from less runoff and evaporation, not from shorter runtimes.

If your tuna can numbers say your zones deliver more or less than typical, adjust in proportion. That is the whole point of measuring.

Shade changes the math too. A zone under mature oaks uses noticeably less water than the same zone in full sun, so I cut shaded zones back by a quarter to a third and let the grass tell me if I went too far.

Drip zones for beds and foundation watering run on their own logic entirely: longer, slower, and by season. Do not try to force them into the lawn's schedule; give them their own program.

Split It: Clay Forces Cycle and Soak

Here is where DFW breaks the textbook. Blackland Prairie clay accepts water slowly, reaching field capacity after roughly a quarter inch. Water past that point does not soak in, it runs down the gutter.

So you never run those daily totals in one shot. Cycle and soak: split each watering day's runtime into two or three shorter cycles spaced about 90 minutes apart, so each cycle stays under the soil's intake limit and the pause lets it percolate.

• A 14-minute spray day becomes 2 × 7 minutes.
• A 28-minute rotor day becomes 2 × 14 minutes.

Two more ways to get the same result without doing it by hand. Some controllers have a built-in cycle and soak function that splits runtimes for you automatically. It is more common on commercial-grade clocks than on basic residential ones, but check yours; if it is there, use it instead of juggling start times. And smart controllers like Rachio do it from your soil and slope settings, which I cover in the cycle and soak guide. The deeper soil mechanics are in clay soil irrigation design.

How Often, Season by Season

Frequency is the seasonal dial. Deep and infrequent beats shallow and daily: watering fewer days at proper depth grows roots that survive August.

• Summer: your restriction maximum, usually twice a week under NTMWD-area rules.
• Spring and fall: once a week is usually plenty.
• Winter: most lawn zones can go dormant-dry except during extended dry spells. Foundation drip keeps running on its own reduced schedule.

Most cities in our service area limit spray irrigation to two days a week with no watering between 10am and 6pm, and those two days are assigned by address. Drip is exempt. The month-by-month numbers, including the restriction rules, are in the DFW seasonal watering schedule; this guide is about building the runtimes that plug into it.

The Best Time of Day

Set the schedule to finish around sunrise. In practice that means first cycles starting between 3am and 5am for most systems.

• Evening watering leaves grass wet all night, which is a standing invitation for brown patch and other fungal disease in our humid springs.
• Midday watering loses a meaningful share to evaporation and usually violates the 10am–6pm restriction window anyway.
• Pre-dawn watering has the best pressure, the least wind, the least evaporation, and the grass dries as the sun comes up.

Putting the Schedule Into the Clock

You now have, for each zone: a cycle length, a number of cycles, watering days, and a finish-by-sunrise target. Every clock I see on garage walls around the Metroplex, the Rain Bird ESP series, the Hunter Pro-C, the Orbit units, expresses that with the same three building blocks:

• Zone runtimes are your cycle length, not your daily total. If the spray zone needs 2 × 7 minutes, the runtime is 7.
• Start times create the cycles. A start time runs the whole program once, so two start times 90 minutes apart, say 4:00am and 5:30am, produce the cycle-and-soak split automatically.
• Programs (A/B/C) separate things that live on different logic. Lawn zones on program A with two start times on your two allowed days. Drip and foundation zones on program B with their own days and durations.

Now the mistake I find on half the controllers I open: a pile of start times on one program. Somebody thought start times were per zone, so there are four start times stacked around 5am, and the program has been quietly running four times every watering day. The homeowner is fighting fungus and a water bill and has no idea why. You need one start time per cycle. Two cycles, two start times. That is it. If your grass squishes and you did not schedule that, count your start times before you blame anything else.

A worked example for a two-day, four-zone system: Program A, watering days Tuesday and Friday, start times 4:00am and 5:30am. Runtimes: zone 1 (spray) 7 min, zone 2 (spray) 7 min, zone 3 (rotors) 14 min, zone 4 (rotors) 14 min. Each start time runs all four zones in order, about 42 minutes end to end, and the second pass finishes a little after 6am.

The button-by-button walkthrough, including seasonal adjust percentages and the rain sensor, is in my controller programming guide.

Or Let a Smart Controller Do the Math

Everything above is what a weather-based smart controller does automatically: it knows each zone's head type, calculates runtimes, splits cycles for clay, skips rain days, and dials frequency up and down through the seasons. If you would rather set the zone details once and never touch the schedule again, that is genuinely what smart controllers are for, and we set them up as a service, configured for DFW clay and your city's restriction days rather than the factory defaults.

When to Call a Pro

Building and programming the schedule is honest DIY territory, and this guide plus the tuna cans will get you a better schedule than most systems in the Metroplex are running. Call a professional when the schedule uncovers hardware problems it cannot fix:

• The catch cans show wildly uneven coverage inside one zone
• One zone is mixed sprays and rotors and needs its heads matched
• Pressure is so low the last heads barely pop, or so high everything is misting
• The controller will not hold a program, or zones run when they should not

Those are repair and diagnosis calls, quoted per job after we see the yard. My sprinkler repair cost guide covers what common fixes run in DFW.