Lawn irrigation is an integral part in the overall lawn care program hence you should acquire the proper know-how.
Should you water your lawn, always soak it to some depth of six to eight inches.
This stimulates the grass to grow a deep, extensive root system which will enable the plant to withstand heat and drought stress.
Light, frequent watering on fully developed lawns results in a shallow root system that gets drier quickly and may die during hot, dry times.
Do not sporadically water your lawn during droughts to a point that your grass gets into various state many times without allowing it to totally recover.
Some grasses, Kentucky bluegrass for example, can survive prolonged droughts within a dormant condition and then resume growth when a sufficient amount of water can be acquired, but this is achieved at great expense to your plant.
Should you begin an irrigation program to care for your lawn, do not ever stop it suddenly in the middle of a stress period.
On bluegrass, it can cause a lot of harm.
It is far better to allow it to harden naturally and get by the hot, dry period during a dormant condition.
Know When to Irrigate The most efficient irrigation only wets the turf grass root zone, will never saturate the soil and doesn't stand in puddles, evaporate or run off.
To find out if your lawn needs watering, look for these symptoms of stress:

• Bluish grass spots inside the lawn.
  
• Footprints that remain in the grass a long after the marks have been made.
  
• Leaf blades folded in a half lengthwise or rolled on the edges.
  
• Soil within the root zone that feels dry.
  

High temps, strong winds and low humidity that go with long dry spells can cause these symptoms.
Water your lawn when these signs show up.
Waiting longer could cause damage that could never be relieved.
Early morning is the most preferred time to water your lawn.
Winds usually are calm so less water evaporates, and then the foliage dries off through the day.
On summertime, splitting you watering times for warm-season grasses by completing half the necessary amount in the morning and the other half in the evening is an excellent way of using water.
Take extra care watering in the evening as foliage tends to stay wet through the night if too much water is used, which makes the lawn weaker and prone to diseases.
Determine the Amount of Water to Use It is a waste to put on more water than the soil can take, plus the kind of soil you have influences how fast water is utilized.
As an illustration, water penetrates sandy soil faster than clay soil.
On sloping lawns, water might run of without penetrating the soil, so apply water slowly in order that the soil will absorb it.
How often you water as well as how much water you are applying every time depends on the kind of grass and the type of soil you have, along with the weather and other factors like heat, wind or humidity.
To determine just how much water to use on your lawn so that it gets soaked 6 or 8 inches deep, you should know the amount water your sprinkler applies.
You can figure this out with a hose-end sprinkler or even an underground system using this method:

1. Put down several straight-sided cans evenly spaced inside a straight line going away from the sprinkler in four directions.
   
2. Run the sprinkler for an hour and then look at the volume of water in each can.
   
3. Take this measurement to calculate just how long you need to run the sprinkler to utilize the proper amount of water.
   

Observe to find out whether runoff is occurring.
In this case, you might want to start and stop your sprinkler at intervals permitting time for the water to absorb into the soil.
Also check to see whether each can contains different quantities of water.
If that's the case, your sprinklers aren't supplying water evenly.
As you work and tweak your watering, you'll get the knack at lawn irrigation.