True, water is essential to lawns. But too much or too little can harm them. Running the sprinkler all night sets up the right conditions for disease. Frequent, light watering causes the grass to grow shallow roots and sets your lawn up for trouble in hot weather. Here are a few easy pointers for correct watering.
Mother Nature usually provides enough water through rainfall for grass to grow strong. However, there are times when rainfall needs to be supplemented, such as with newly planted lawns or extended periods of heat and drought. If you choose to water, wait until the lawn becomes dull green in color and footprints remain visible in the grass.
Be sure to water deeply and infrequently. Avoid watering from 11 AM-3 PM, the hottest part of the day. It is best to water between 6-10 AM. There's less wind, less hot sun, and your lawn has a full day to dry. Watering at night invites mildew and fungus but if you can't water in the morning aim for around 4-7 PM. In the hot afternoon, much of your water can be lost to wind and evaporation. If you live in the dry southwest, though, the rules are different. There, watering in the evening or night causes less evaporation.
If using sprinklers, apply about a ½ inch of water twice per week. To know how long it takes to apply that much water, set out empty tuna cans to measure it and determine the time needed to apply a good thorough watering. It could take between 15 and 30 minutes depending on the type of sprinkler you use. Also, sprinklers don't always put water down evenly. To make sure water is going where it's supposed to, check to see that the water levels in the tuna cans are equal to know your sprinkler is doing its job.
How do you know how much you've watered unless you've measured? That's what's nice about water gauges. At a glance, you can tell how much water has gone on your lawn - either from your sprinkler or rain. You'll find gauges at most lawn and garden centers.
Another watering alternative during prolonged drought is to let the lawn go dormant and turn brown. Lawns are amazingly resilient and can tolerate dry conditions for up to 2 months if left alone. Grass will bounce back when rainfall and cooler temperatures return in the fall, especially if it was well fed in the spring.
However, if the lawn is used frequently by kids or pets during the hot summer, consider watering if not prohibited by local water restrictions. Dormant lawns can't tolerate a lot of use, so foot traffic from play or parties can damage dormant grass. Before you water, make sure rain is not predicted in the next few days, and if so, let Mother Nature be your sprinkler. If not, water deeply 1-2 times per week with no more than ½ inch of water each time.