Irrigation

• Why do we have this rule?
• Irrigating during the hours when it will do your lawn and landscapes the most good can save you money on your water bill, or on your electric bill if you have a private well and pump.
  
• When you water your lawn and landscapes before 10:00 a.m. or after 4:00 p.m., the water can seep into the ground where thirsty grass and plant roots can drink up the water, promoting healthy plants that establish deep root systems.  Water sprinkled on lawns during the hottest part of the day is wasted. During the heat of the day, 65 percent of that water evaporates.  Water droplets on plants can act like a magnifying glass, causing the sun to burn the leaves.
  
• Though Florida usually receives about 50 inches of rain each year, only a small amount seeps into the ground to replenish underground aquifers. Aquifers are where 90 percent of us in north and east central Florida, the region of the SJRWMD, get our drinking water.
• How much water is enough? 
  A rigid irrigation schedule is not necessary, especially when Mother Nature helps water your landscape with rain. In general, most Florida grasses need only about 2/3 to ¾ of an inch of water each time it rains or you irrigate. Apply only enough water to wet the grass’ root system. Do not saturate the soil so fast that runoff occurs. You have several options to help determine how much water to apply to your lawn. You may:
• Use a water meter which is permanently installed in the irrigation line. This will indicate the number of gallons applied per minute, allowing you to accurately determine the number of minutes necessary to apply the correct water volume.
• Use a rain shut off device on your automatic timed sprinkler system. This device overrides a sprinkler system in the event of a specific amount of rain. It also resets the sprinkler system for normal operation when the turf requires more water.
• Use a soil moisture sensor. The sophisticated sensors will activate your irrigation system when water is needed. The more basic soil moisture sensors turn off your irrigation system when water is adequate or when it is raining.
• Use the in-place measurement of watering by the "can method." Place five to seven wide-mouthed, flat bottom cans on diagonals throughout the irrigated area.
• Water for 15 minutes, then measure the depth of the water in each can. Average the measurements and use this to deter-mine how long you need to irrigate to apply 2/3 to ¾ of an inch of water.  Watering needs change throughout the year. Following are grass water needs when rain is not available:
  • Between April and August, irrigate about every three to five days.
  • In September and October, water every five to seven days.
  • During the winter months, lawns need water only once every 10 to 14 days.

Two ways to determine when to water your lawn are 1) visual inspection and 2) direct measurement of soil moisture.

Visual inspection – The most efficient way to water your lawn is to irrigate when it shows signs of stress from a lack of water. Visual signs of water stress include the lawn turning a bluish-gray color, footprints lingering after being made, leaf blades folding in half, and/or soil from the root zone feeling dry.

Direct measurement of soil moisture – One way to measure soil moisture is with a soil moisture sensor. There are sophisticated sensors which will activate your irrigation system when water is needed. The more basic soil moisture sensors turn off your irrigation system when water is adequate or when it is raining.

Tips for a healthy lawn…

• Water early in the morning. This reduces evaporation by the hot sun and takes advantage of less wind. Also, watering early reduces the potential for disease development.
• Do not over fertilize. Fertilizers stimulate growth, fungus, and increased water needs. If you do fertilize, use a slow release nitrogen product.
• Raise the height of your lawnmower blades. When you mow, remove only the top one-third of the grass. Cutting grass shorter than that decreases the depth to which roots will grow, increasing their need for water. Most St. Augustine and Bahia grasses should not be mowed shorter than three inches in height.
• Leave short grass clippings where they fall. The clippings reduce the lawn’s need for water and fertilizer. Remove thick patches of clippings from turf so that the clippings will not kill the grass underneath.
• Keep lawnmower blades sharp to cut clean. Grass torn and shredded by dull blades suffers stress and requires more water.
• Inspect your sprinkler system frequently. Look for breaks, a uniform spray pattern, and proper timing.

For More Information

To learn more about the Water Conservation Rule, exceptions to the rule, or for tips on conserving water inside and outside, call The St. Johns River Water Management District’s Office of Communications at 1-800-725-5922 or visit their website at http://www.sjrwmd.com.

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