Stop guessing with your sprinkler timer. Learn the science of deep watering to promote drought-tolerant roots and avoid fungus in St. Augustine and Zoysia lawns.

The Science of Watering

Watering your lawn seems simple: turn on the hose, get it wet, turn it off. However, in Florida's sandy soil and intense heat, improper irrigation is the #1 killer of sod. Shallow watering encourages shallow roots. Evening watering encourages fungus. To maintain a drought-tolerant, disease-free lawn, you must follow the "Golden Rules" of irrigation.

Rule #1: The 4:00 AM Start Time

The single best time to water your lawn is between 4:00 AM and 8:00 AM.

Why Morning?

Wind is calm: The water goes where you aim it, not onto your driveway.
Evaporation is low: The water has time to soak into the root zone before the sun burns it off.
Disease Prevention: This is critical. If you water in the evening (6 PM - 10 PM), your grass stays wet all night. Warm, wet, dark conditions are a petri dish for Fungus (Large Patch, Grey Leaf Spot). By watering in the morning, the sun dries the blades quickly, preventing disease.

Rule #2: Deep and Infrequent

Your goal is to train your grass roots to grow deep. Roots follow the water.

The Wrong Way: Watering for 10 minutes every day. This keeps the top inch of soil wet. The roots have no reason to dig deeper. When a drought comes (or you miss a day), these shallow roots fry, and your lawn dies.

The Right Way: Water for 45-60 minutes, twice a week. This "Deep Soak" forces water 6-8 inches down into the soil. The roots must stretch down to find it. This creates a robust, drought-tolerant root system that can survive days without water.

Rule #3: The "Tuna Can" Calibration

A timer setting of "30 minutes" means nothing. One zone might have high-flow rotors, another might have mist heads. You need to measure the volume of water, not the time.

The Test: Place empty tuna cans (or straight-sided coffee mugs) around your lawn. Run your sprinklers for 30 minutes. Measure the water depth in the cans.

Target: You want 3/4 inch of water per session.
Math: If you get 1/4 inch in 30 minutes, you need to run that zone for 90 minutes to get the proper soak. Adjust your timer accordingly.

Rule #4: Watch the Weather (and the Law)

Jacksonville (St. Johns River Water Management District) has strict watering restrictions.

During Daylight Savings Time (Spring/Summer): You may water twice a week on your designated days.
During Eastern Standard Time (Fall/Winter): You may water once a week.
Never water between 10 AM and 4 PM. It is wasteful and illegal.

Also, install a Rain Sensor. It is required by Florida law on all automated systems. It shuts off your system after heavy rain, saving you money and saving the grass from root rot.

Summary

Irrigation is not "set it and forget it." It is a tool. Use it wisely. Deep, infrequent, morning watering is the secret to the lush, green lawns you see in magazines.

The Golden Rules of Irrigation in Northeast Florida