Giving your lawn a big gulp of water is better than giving it a series of sips. Roots grow where the water is. If you water deeply, you will develop a deep root system. On the other hand, if you only sprinkle the surface of the soil, you will create a shallow root system.
If you have a clay soil, irrigate only once or twice a week. Sandy soils can’t hold a full inch of water, so we will need to split the application to two or three times a week. Split applications are also a good idea if you see water running off from the lawn (for example, on a sloped landscape). We want the water to be absorbed and not to run off.
The grass plants will be active and will absorb the water they need. Any extra water will evaporate, keeping the grass blades dry and preventing diseases. Watering during the middle of the day is not recommended since much of the water you apply will evaporate before the plants absorb it. Watering is the evening is not recommended since the lawn will stay wet all night, leading to diseases.