I was asked by the owner of a commercial yard crew this past week to take a look at one of his customers lawns. There were large dead spots across on otherwise nice-looking landscape.
The turfgrass was struggling and had what appeared to be a fungal disease. At first glance, you might assume the grass needed more water. But the irrigation system was running nearly every morning, and excessive irrigation combined with too much fertilizer may have actually helped create the problem.
It is truly hot and dry in East Texas. That means lawns, landscapes, gardens and everything else growing outside are using water quickly. For many homeowners, the natural response is simple: water more.
And I strongly suspect that the frequent, shallow watering, combined with excessive fertilization, contributed to the fungal disease and large dead areas of turf. So, before you add another day to your irrigation schedule, make sure you are adding water correctly. A sick lawn isn’t necessarily a thirsty lawn.
Look at the grass. Wilting, or perhaps an off color of green, and certainly footprints that remain visible after you walk across the lawn are signs of drought stress.
The perfect tool for your water management is a long screwdriver. You use it by pushing it the soil. If it easily penetrates the soil several inches, there is still moisture present in the root zone.
Established turfgrass generally benefits from deeper, less frequent irrigation rather than a little water every day. Frequent, shallow irrigation encourages a shallow root system and can keep the soil surface continually wet—conditions that can contribute to turfgrass disease.
Let me say that again, but in a different manner. No one is suggesting to limit the volume of water you put on your lawn. It is strongly suggested, however, that you water in a manner so that it goes deeper but with less frequency.
When you do irrigate, early morning is generally the best time. Avoid irrigating late in the evening when possible because prolonged leaf wetness can increase the opportunity for some turfgrass diseases.
If you have an automatic sprinkler system, now is also a great time to give it an irrigation audit.
Start by turning on each zone and watching it operate. Do all the sprinkler heads pop up? Are any broken, leaning or clogged? Is water spraying onto the driveway, sidewalk or street? Are shrubs blocking the spray pattern?
These problems are easy to fix, but a broken sprinkler head can waste a surprising amount of water over the course of a summer.
Next, determine how much water your system is actually putting on the lawn.
Place several small, straight-sided containers or rain gauges throughout a sprinkler zone. Run the system for 10 or 15 minutes and measure how much water each container collects. This will tell you how evenly your system is applying water and how much water is being delivered in a given amount of time.
Now watch the lawn while the system is running. If water begins running off the lawn and down the driveway or street, your soil cannot absorb water as quickly as you are applying it.
The solution is a practice called “soak and cycle”. Instead of running a sprinkler zone continuously until runoff occurs, stop the irrigation and allow the water to soak into the soil. Then run that zone again. You may need two or three cycles in a morning to apply the amount of water you need without wasting water to runoff.
The goal is to put water deep into the root zone, not simply wet the surface.
Two huge benefits come of this. First, your lawn develops a deeper root system that will benefit it in so many ways. Second, you allow the surface of your turfgrass to dry between irrigations, which can reduce conditions favorable to some fungal diseases. That was likely the problem with the landscape company’s lawn mentioned at the beginning.
Finally, don’t try to solve a struggling lawn by automatically adding fertilizer.
Nitrogen can make grass grow rapidly, but more fertilizer does not necessarily mean healthier grass. Excessive nitrogen and irrigation can contribute to disease problems. If your lawn is struggling, determine why before reaching for the fertilizer spreader.
It is easy to look at a brown lawn in August and assume it needs more water.
Sometimes it does.
Sometimes it needs a broken sprinkler head repaired. Sometimes it needs better irrigation scheduling. And sometimes it needs to watered for a longer time on fewer days!
This August, before you turn up the irrigation system, take a few minutes to see where your water is going.
Measure it. Watch it. Adjust it.
Your lawn—and your water bill—will thank you.
