Even with flood conditions recently, I’ve seen irrigation systems going full blast.
When the soil is saturated, you can’t make it anymore wet. When a glass is full, you can’t add more water. We should irrigate lawns, landscapes and gardens on an as-needed basis, when there is a need for water.
An irrigation system is a tool to supplement rainfall, not to water in addition to rainfall.
Did you know it has been state law in Florida since 1991 for every irrigation system to have a rain sensor device installed to prevent an irrigation system from coming on while it’s raining or when adequate rainfall has occurred? Florida Statutes Chapter 373 reads, “Any person who purchases and installs an automatic lawn sprinkler system after May 1, 1991, shall install a rain sensor device or switch which will override the irrigation cycle of the sprinkler system when adequate rainfall has occurred.” Rain shutoff devices are readily available and are in the twenty to thirty dollar range.
To avoid over-watering, let your lawn tell you when to water. Your lawn is telling you it needs water when you see dull, bluish-gray areas in the lawn, footprints remain in the grass long after being made and leaf blades are folded in half. When 30 – 50 percent of your lawn shows these signs, it should receive about ½ inch of water. The most efficient time to apply water is during early morning hours. Don’t water again until the water need signs are visible. The best time to observe these signs of water need is during the evening when the grass is not in full sun.
To determine how long it takes to apply ½ inch of water, set out coffee or tuna fish cans in the irrigated area and see how long it takes to fill them to the desired depth.
By watering this way, your lawn will develop a deep, strong root system that will better withstand drought and heat and you’ll minimize root diseases, too.
Once your lawn has developed a deep root system, it will do perfectly well on 2 to 3 waterings per week during the hot summer months and once every 10 to 14 days in winter. When we receive adequate rainfall, no irrigation will be needed.
Learn to cut your automatic irrigation controller to off, install a rain shutoff device and water your lawn on an as-needed basis. Your lawn and your pocketbook will profit.
For reliable information on lawn care, contact your UF/IFAS County Extension Office or visit http://edis.ifas.ufl.edu/topic_lawn_watering.