Proper Watering Techniques
A well maintained lawn needs a minimum of 1 - 1 ½ inch of water per week while it is growing. The growing season is divided into 3 parts; first, is Spring when rain is generally adequate for lawn watering. Second is the Summer drought during which time the lawn naturally goes dormant and looks like it needs water. Pick your watering strategy from below to fit your circumstances. And, third is the Fall when the lawn begins growing again. You should begin watering on a weekly basis to store water in the soil to help the lawn "winter over" in better shape.
Remember: WATER IN THE MORNING and mow in the evening. A corollary is water when ever is best for your schedule. Watering at a time that is not optimal is better than not watering at all. We advise watering in the morning because the lawn needs time to dry off to reduce the incidence of lawn diseases (fungi). We advise watering at sub-optimal times because a lawn without water is a stressed lawn and a stressed lawn is susceptible to lawn diseases.
Watering depth should be determined by the rooting depth. In our "clayey" soils that is going to be around 3-4 inches for a well developed lawn. To test for adequate watering depth see if you can easily sink a 6" screwdriver in the ground to a depth of 3 - 4 inches. You can also set a straight-sided pan out under your sprinkler to see if you have gotten the required 1 inch of water. It should take an hour or more for this requirement to be filled.
Proper Watering Technique is Defined As: If you do water, then water deeply. That means you should prepare the soil to receive water by wetting the surface first by watering for 15-20 minutes. Let the soil "relax" by shutting the water off for 20-30 minutes. Then water the lawn for 1 to 2 hours per setting. Water every week to ten days.
Drought Strategy One: Commit to watering regularly every week to ten days throughout the summer drought. Swttch to one of the other strategies when/or if water bans are called for by the authorities.
Drought Strategy Two: The lawn has gone dormant (a natural thing) to protect the living crowns of the grass plants. The lawn can remain dormant for 6 to 8 weeks before the crowns are damaged. DO NOT water unless you are prepared to water throughout the remainder of the drought. After 6 weeks you should water deeply every week to 10 days.
Drought Strategy Three: If you have watered deeply recently and the heat and wind pick up, think about "syringing" the lawn as the golf courses do. Syringing is lightly watering the lawn surface to cool it off. The area to "syringe" would be the "curb appeal" area that makes your home look nice. The rest of the lawn can do without,
Drought Strategy Four: Save your trees and shrubs by watering them with drip irrigation or trickle watering for 2 to 4 hours every week. This does not take too much water and is done to the base of each tree or shrub. There are kits for drip irrigation and leaky hose in the hardware stores. Mulching 1-2 inches over the roots of the trees and shrubs will help reduce water evaporation from the root area. Watering trees and shrubs is more important than watering your lawn as it is much easier to replace your lawn should you lose it.