Eating tuna can result in a healthier lawn. Well, it’s not the tuna; it’s the tuna cans that can help.
In order to water correctly, you need to calibrate your irrigation system. The tuna cans will help you do this.
To calibrate the sprinkler system, place empty tuna cans (or other straight-sided cans) on the ground in the area to be irrigated so that they catch the irrigation water. The more cans the better – use at least 10 cans per irrigation zone. Cut the water on, let it run for 15 minutes and then carefully measure the water collected in each can with a ruler. Now find the average amount of water collected by adding up the depths and dividing by the number of cans. Another way to do this is to carefully and completely empty the contents of each can into one of the cans, measure the depth of water in that can and divide by the total number of cans. This will give you the average amount of water applied by the system during the 15 minutes. For example, if you collect an average of one-quarter inch in 15 minutes you will need to run your irrigation system for 30 minutes to apply one-half inch or for 45 minutes to apply three-quarters inch, etc. Calibrate each zone separately.
Knowing the amount of water each irrigation zone applies is a must in order to water correctly.
One of the better ways to water is to apply one-half inch of water when the lawn begins to show water deficiency symptoms. Footprints or tire tracks that remain long after being made indicate the need for water in a lawn. Folded leaf blades also indicate that it’s time to water. Many blades will fold along the mid-leaf vein (like a book closing) when water is needed. Wilted, bluish-gray areas in the lawn are a third indication of water need. When 30 percent to 40 percent of the lawn shows these signs of water need, apply one-half to three-quarters of an inch of water. Don’t water again until the lawn exhibits the need for water.
Calibrating your sprinkler system and water on an as needed basis (compared to shallow, frequent watering) will allow your lawn to develop a deeper, healthier root system. The lawn will be more competitive with weeds and diseases, too. And, you might even save some time and money on lawn disease and weed control.
So start saving those tuna cans and calibrate your irrigation system.