Watering Your Lawn
Wise watering practices not only conserve water but help to build a stronger, healthier lawn. Constant over watering or frequent underwatering promotes shallow roots, a sure way to damage your lawn during times of stress. These stressful times for your lawn include not only the hot summer months, but also the cold winter months when there is really nothing you can do for an unhealthy lawn. The healthiest lawns have the healthiest roots. The best watering practices moisten the soil 4-6 inches deep; this is the extent of the root zone, and requires only about 1 inch of water.
When to water your lawn
How much water do I need to moisten the soil 4-6 inches deep?
How do I know when I've put out 1 inch of water?
How else can good watering practices help my lawn?
Overwatering can cause runoff. Runoff occurs when the water falling on the soil exceeds the amount that can be absorbed at that time. This can lead to fertilizer runoff, erosion, loss of newly sown seed, and water dollars washing down the street. If the time it takes for you to put out 1 inch of water causes runoff, then divide that time in two and leave some time in between. This is a good practice to follow on slopes where runoff obviously occurs more quickly.
Cool season lawns, like fescues and bluegrass, naturally go dormant in the heat of the summer. If you practice good watering techniques your healthy lawn will go dormant in the summer and only needs watering every 3 weeks if there has been no rain. That healthy lawn will bust out again in September as thick and green as ever.
Overwatering or watering improperly in the summer, when your cool season grass naturally goes dormant, increases the growth of those heat loving, actively growing weeds which you will be watering, and therefore weeding. Also, it puts the plant in an unnecessary state of stress. Also, it "tricks" the plant into "thinking" it has enough water and if water restrictions take effect, your grass will likely die.
So give your lawn a break for a month or two - let it go dormant - and someday when you get the opportunity to take off two months, maybe no one will bother you.