Who would have thought that about 10 days ago Oklahoma had so much rain that we were under flash flood warnings. You sure wouldn’t know it when you look around now. We are barely a week into the official start of summer, and already we have had multiple days of extreme heat. You know, the kind of heat that just makes you want to stay inside with the air conditioner on high, eating a 
popsicle, and taking it easy. It also seems that with the onset of the heat, our chances of rain have dwindled to nothing. But what can I say, we do live in Oklahoma!
So with the hot and dry conditions in place for a while, it would probably be a good thing to have a refresher course on watering your lawn and landscape.
Water Deep, But Not Everyday
Most turfgrasses will need about 1.5”- 2” of moisture per week in order to perform their best. Warm-season grasses such as Bermudagrass love hot weather, as long as there is adequate soil moisture available. Cool-season grasses, such as Fescue, can go semi-dormant in some areas with hot temperatures and inadequate soil moisture. Another problem is that during the summer, not only is the turf absorbing and using great amounts of water in order to grow and cool off, but the hot sun is drying out the soil moisture also. Turf roots can grow deep though, so one key is to water deeply so that the soil will be moist 6”-8” below the surface. This “trains” the roots to grow deep, and be able to absorb that deep soil moisture.
We find that many homeowners with sprinkler systems actually can hurt their turf’s ability to withstand summer stress by watering every day. This keeps the top inch or two of soil so moist that the turf roots just concentrate right at the surface. Roots are a lot like people—they’ll only go where they need to! So by daily watering, you are actually training your root system to be shallow, making it become addicted to daily watering.
So go ahead and allow the top surface of your soil to dry out a little between waterings. It’ll be OK! A little stress will help your root system to grow deeper. Then when you do water, water well, supplying up to an inch of water so that the deeper soil layers become moist. If you have a clay soil or one that has a hard time absorbing water well, you’ll need to water in increments so that the water will not run off. I’d suggest going through your sprinkler cycle twice, allowing some time for the water to be absorbed in-between cycles.
If we receive rainfall during the week, then obviously you can cut back on your irrigation. A general rule-of-thumb is about 1.5” to 2” per week, either from rainfall or irrigation. So if we have no rain, as often is the case during summer and early fall, you’ll need to water 3-4 times per week, as long as you water long enough to put out ½ to 1” of water each time you irrigate.
End Your Irrigation at Sunrise
The best time to water is early in the morning, before the sun comes up. This will allow the water to penetrate into the soil, while allowing the morning sun to dry out the grass so that it won’t stay damp too long. Watering too much in the evening can lead to turf disease, such as Brown Patch, Rust, and Pythium. Watering in the early morning hours is pretty easy for those who have a sprinkler system, or for those of us who are wide awake at 5:00 in the morning. But if you like to sleep in, and don’t have a sprinkler system, then you have to water when you can, because in a hot and dry Oklahoma summer watering at the wrong time of day is better than not watering at all!
Don’t Forget Yourself
Just as your lawn and landscape needs adequate amounts of water to thrive, so do you. So while you are outside enjoying your lawn, make sure you drink plenty of water, take plenty of breaks in the shade, and don’t overdo it. I don’t know about you, but I think it’s about time for that popsicle!
Tags: Irrigation, Summer, watering
